The Ultimate Make-Ahead Sausage and Mushroom Breakfast Casserole: Perfect for Holidays & Brunches
Imagine waking up on a special morning, the aroma of a delicious, savory breakfast filling your home, without having lifted a finger in the kitchen that day. This dream becomes a reality with our incredible make-ahead sausage and mushroom breakfast casserole! Combining the hearty flavors of browned sausage and tender mushrooms with fluffy eggs, rich cheese, and a luscious homemade mushroom gravy, all layered over soft bread, this dish is an absolute showstopper. It’s not just a meal; it’s an experience, making it the ideal choice for festive holidays, relaxed brunches, or any occasion where you want to impress with minimal morning effort.
For me, this casserole carries a profound sense of nostalgia. Growing up, Christmas morning always meant a trip to my grandparents’ house, where after the flurry of unwrapping presents, my grandma would greet us with this very sausage and mushroom breakfast casserole, hot and ready from the oven. It was a cherished tradition, a comforting start to a joyful day, and a dish that truly defined holiday mornings. That warm memory inspired me to recreate her beloved recipe, with a few modern updates to enhance the flavors and simplify the process, all while preserving the essence of what made it so special.
The result is a dish that is every bit as delicious and satisfying as I remember, perhaps even more so. It embodies everything you could wish for in a savory make-ahead breakfast, offering both convenience and gourmet taste for those truly special occasions. This casserole isn’t just a recipe; it’s a culinary journey back to comforting traditions, perfected for today’s busy lifestyles.
Table of Contents
- Why This Make-Ahead Breakfast Casserole is a Must-Try
- Essential Ingredients for Your Casserole
- Step-by-Step: How to Prepare Sausage and Mushroom Breakfast Casserole
- Expert Recipe Tips for the Best Casserole
- Delicious Serving Suggestions
- More Inspiring Make-Ahead Breakfast Ideas
- Get the Full Recipe
Why This Make-Ahead Breakfast Casserole is a Must-Try
You are truly going to adore the harmonious blend of flavors in this savory breakfast casserole. It’s a symphony of robust sausage, earthy mushrooms, sweet onions, and sharp cheddar cheese – a combination that simply sings on the palate. Every bite offers a delightful mix of textures and tastes, making it an incredibly satisfying start to any day.
However, what truly elevates this dish from simply good to absolutely unforgettable is the rich, creamy mushroom gravy generously spooned over the top. This isn’t just any gravy; it’s a homemade masterpiece that infuses the entire casserole with an unparalleled depth of flavor and ensures every piece remains wonderfully moist. While my grandmother traditionally used a can of cream of mushroom soup for convenience, I’ve developed a scratch-made version that brings an extra layer of gourmet quality to the dish. The best part? You have the flexibility to choose either option, depending on your time and preference, without compromising on taste!
One of the most appealing aspects of this breakfast casserole, much like many beloved breakfast bakes, is its incredible make-ahead capability. You can fully assemble this culinary delight the night before, allowing all the flavors to meld beautifully overnight. Then, come morning, simply pop it into the oven to bake fresh. This means you can enjoy a sumptuous, homemade breakfast without any frantic cooking on the day of your event, freeing you up to relax and savor the moments. It’s genuinely perfect for special occasions like Christmas, Thanksgiving, Easter, or any holiday where a stress-free, delicious meal is paramount. Many readers have shared their delight, with one reviewer, KJT, exclaiming, “This is by far, the best version of this egg-with-bread-in-the-bottom casserole I have tried. The taste is exquisite. My entire family loved it, so no leftovers, darn it!”
Essential Ingredients for Your Casserole
Crafting this hearty sausage and mushroom breakfast casserole requires a selection of fresh, high-quality ingredients that come together to create its signature rich flavor. Here’s a detailed look at everything you’ll need to gather to prepare this delightful dish. You can find the precise measurements and further details in the full recipe card located at the bottom of this page.
- **Butter:** Essential for sautéing and creating the roux for our creamy gravy, adding richness.
- **Ground Breakfast Sausage:** The savory backbone of the casserole, choose your favorite style (mild, hot, or sage).
- **Button, Cremini, or Baby Bella Mushrooms:** These varieties offer a deep, earthy flavor and satisfying texture when sautéed.
- **Onion:** Adds a subtle sweetness and aromatic depth to the savory components.
- **Cheddar Cheese:** Melts beautifully and provides a sharp, tangy counterpoint to the other ingredients.
- **Eggs:** The binding agent for the casserole, creating a custardy texture.
- **French Bread or other Loaf of White Bread:** Acts as the foundation, soaking up all the delicious liquids and flavors. Stale bread works best for this.
- **Milk (preferably whole milk or 2%):** Used in both the egg mixture and the homemade gravy for creaminess.
- **All-Purpose Flour:** The key ingredient for thickening the gravy into a smooth, luxurious sauce.
- **Salt and Pepper:** Fundamental seasonings to enhance all the flavors. Adjust to your personal taste.
- **Fresh Chives:** An optional but highly recommended garnish, adding a touch of fresh oniony brightness and vibrant color.
Step-by-Step: How to Prepare Sausage and Mushroom Breakfast Casserole
Creating this magnificent breakfast casserole is simpler than you might think, especially with its make-ahead convenience. Follow these clear steps to assemble a dish that will surely become a family favorite.
- Brown Sausage, Mushrooms, and Onions: Begin by browning your ground breakfast sausage in a large skillet over medium-high heat until it’s fully cooked and beautifully golden. Once done, remove the sausage from the skillet and set it aside, leaving any drippings behind. Next, add a portion of butter to the same skillet, then introduce your sliced mushrooms and chopped onions. Season lightly with salt and pepper. Cook, stirring occasionally, until the mushrooms are tender and the onions have softened and become translucent, typically about 5 minutes. Remove these from the skillet and combine them with the cooked sausage.
- Prepare the Homemade Gravy: Using the same skillet, melt the remaining butter. Once melted, whisk in the all-purpose flour to create a “roux” – a thick paste that will serve as the base for your gravy. Cook this roux for about 1 minute, allowing it to toast slightly and deepen in flavor. Gradually add 1 cup of milk, whisking continuously to ensure a smooth consistency and prevent lumps. Continue to whisk as you bring the mixture to a gentle simmer, allowing it to thicken into a creamy, luscious gravy. Season this rich gravy with salt and pepper to taste, ensuring it’s perfectly balanced. Set the gravy aside.
- Assemble the Casserole Layers: Prepare your 9×13-inch casserole dish by lightly greasing it. Spread the cubed bread into an even layer across the bottom of the dish; this will form the absorbent base of your casserole. In a separate bowl, whisk together the eggs, the remaining milk, and the melted butter. Pour this egg mixture carefully and evenly over the bread cubes, making sure every piece is thoroughly moistened. Next, scatter the cooked sausage, mushrooms, and onions over the bread layer. Follow this by sprinkling half of the shredded cheddar cheese evenly over the top of the sausage and vegetable mixture. Finally, spoon the prepared mushroom gravy in generous drizzles over the entire casserole, creating pockets of rich sauce throughout, and then top with the remaining cheese. Gently press down on the layers with the back of a spoon to ensure everything is cohesive and the bread is fully submerged.
- Chill for Flavor Development: Cover the assembled casserole dish tightly with aluminum foil and refrigerate it for at least 4 hours, or ideally, overnight. This crucial chilling period allows the bread to fully absorb the egg and milk mixture, resulting in a more uniform texture and richer flavor when baked. It’s this step that truly makes it a fantastic make-ahead option.
- Bake to Golden Perfection: When you’re ready to bake, preheat your oven to 350°F (175°C). Place the covered casserole directly from the fridge into the preheated oven and bake for 45-60 minutes. For the last 10-15 minutes of baking, remove the foil to allow the cheese to bubble and brown and the top to achieve a beautiful golden crust. The casserole is done when it’s puffed up and completely set in the middle, with no jiggly spots. If desired, sprinkle with fresh chopped chives immediately after baking for a burst of fresh flavor and color.
- Serve and Enjoy! Once baked, let the casserole rest for a few minutes to set before slicing into generous portions. Serve it hot and watch it disappear!
Expert Recipe Tips for the Best Casserole
Achieving breakfast casserole perfection is easy with these helpful tips and tricks. Whether you’re planning ahead or looking for flavor variations, these insights will ensure your sausage and mushroom casserole is a resounding success.
- How to make this breakfast casserole ahead of time: The beauty of this dish lies in its make-ahead versatility. While you can certainly bake the casserole immediately after assembly, for the absolute best results and a more uniform, custardy texture, I strongly recommend chilling it. This allows ample time for the bread to fully soak up the flavorful egg mixture, preventing dry spots and ensuring every bite is moist and delicious. Preparing it the night before is ideal, as it can be stored covered in the fridge for up to 24 hours before baking. When morning arrives, simply take it straight from the refrigerator and pop it into the preheated oven – effortless entertaining at its finest!
- Using a can of cream of mushroom soup for a shortcut! If you’re short on time or simply prefer the classic approach my grandma used, feel free to substitute the homemade gravy with a can of condensed cream of mushroom soup. For best results, gently warm the soup in a small saucepan or microwave until it has a more spreadable consistency. Then, spoon it evenly over the casserole layers in place of the scratch-made gravy. This is a fantastic time-saver that still delivers a comforting, savory flavor.
- Flavor variations to customize your casserole: Breakfast casseroles are incredibly forgiving and adaptable, making them perfect for customization! Don’t hesitate to experiment with different cheeses – a sharp provolone, a mild Colby, or a spicy Monterey Jack could all offer exciting twists. For a vegetarian option, simply omit the sausage, or try using turkey or chicken sausage for a lighter protein. You can also easily incorporate other vegetables; wilted spinach, diced bell peppers, or even a handful of sun-dried tomatoes would be wonderful additions. And if mushrooms aren’t your favorite, no problem! You can simply leave them out or substitute them with another vegetable you enjoy.
- Knowing when your casserole is perfectly cooked: The key to a perfectly baked breakfast casserole is ensuring it’s cooked through without being overdone. You’ll know it’s ready when the center no longer appears wet or “jiggly.” Gently shake the casserole dish – if the filling is completely set and firm in the middle, it’s done! The top should be golden brown and the edges slightly puffed. An internal temperature of 160°F (71°C) at the center is a good indicator of doneness for egg-based dishes.
- How to reheat leftover breakfast casserole: This sausage and mushroom breakfast casserole reheats beautifully, making leftovers a real treat! To warm up the entire dish, cover it with foil and place it in a 300°F (150°C) oven for about 25-30 minutes, or until thoroughly heated through. Individual slices can also be quickly and conveniently reheated in the microwave; simply place a slice on a microwave-safe plate and heat for 1-2 minutes, or until hot.
Delicious Serving Suggestions
This hearty sausage and mushroom breakfast casserole is a meal in itself, but if you’re hosting a larger gathering or simply want to elevate the spread for a special occasion, here are a few delightful side dishes and beverages that pair wonderfully:
More Inspiring Make-Ahead Breakfast Ideas
If you love the convenience and deliciousness of make-ahead breakfast dishes, you’re in luck! There’s a whole world of recipes that allow you to prepare most, if not all, of the work the night before, leaving you with more time to relax and enjoy your morning. Here are a few more fantastic make-ahead breakfast ideas that are perfect for busy weekdays or special weekend brunches:
- Baked French Toast with Streusel Topping and Cranberry Maple Syrup
- Spinach and Tomato Baked Egg Cups
- Asparagus, Bacon and Cream Cheese Quiche
- Raspberry Almond Baked Oatmeal
Get the Full Recipe
Sausage and Mushroom Breakfast Casserole
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Ingredients
- ½ lb ground breakfast sausage
- 8 ounces button or cremini mushrooms , sliced
- 1 cup chopped onions (½ medium onion)
- 6 tablespoons unsalted butter , divided
- 2 tablespoons all-purpose flour
- 2 cups milk , divided (whole or 2% for best creaminess)
- 1 ½ teaspoons salt , or to taste
- About ½ teaspoon freshly ground black pepper , to taste
- 12 large eggs
- 1 ½ cups shredded cheddar cheese
- 6 cups cubed French, artisan or other white bread (about 8 thick slices, day-old bread works best)
- Chopped fresh chives , for garnish (optional)
Instructions
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In a large skillet set over medium-high heat, cook the ground breakfast sausage, breaking it apart with a spoon, until it is beautifully browned and fully cooked through. This usually takes about 5-7 minutes. Once cooked, remove the sausage from the skillet using a slotted spoon and set it aside in a bowl, leaving any rendered fat in the pan.
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To the same skillet with the sausage drippings, add the sliced mushrooms and chopped onions. Season them lightly with a pinch of salt and pepper. Cook, stirring occasionally, until the mushrooms have released their moisture and softened, and the onions are translucent and fragrant, which typically takes about 5-7 minutes. Once cooked, remove the mushrooms and onions from the skillet and combine them with the browned sausage.
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Now, prepare the homemade mushroom gravy. Melt 2 tablespoons of butter in the skillet over medium heat. Add the 2 tablespoons of all-purpose flour and whisk vigorously to form a smooth, thick paste, or “roux.” Cook this roux for about 1 minute, stirring constantly, to cook out the raw flour taste. Gradually add 1 cup of milk to the pan, whisking constantly to ensure the sauce remains smooth and free of lumps. Bring the mixture to a gentle simmer, continuing to stir until the sauce thickens to your desired consistency. Season this rich gravy with 1 teaspoon of salt and ¼ teaspoon of pepper, or adjust to your personal taste preference. Set the finished gravy aside.
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In a separate medium-sized bowl, melt the remaining ¼ cup of butter. Whisk the melted butter together with the remaining 1 cup of milk and the 12 large eggs until well combined and slightly frothy. Add ½ teaspoon of salt and ¼ teaspoon of pepper to this egg mixture, whisking again to incorporate the seasonings.
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To assemble your delicious breakfast casserole, lightly grease a 9×13-inch baking pan with butter. Spread the 6 cups of cubed bread into an even layer across the bottom of the prepared pan. Carefully pour the whisked egg mixture over the bread cubes, ensuring that all pieces of bread are thoroughly moistened and begin to absorb the liquid. Evenly scatter the cooked sausage, mushrooms, and onions over the egg-soaked bread layer. Then, sprinkle half of the shredded cheddar cheese over the top of the sausage and vegetable mixture.
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Next, spoon the homemade mushroom gravy over the casserole in heavy drizzles. This method helps create delicious pockets of rich sauce among the other ingredients. Finish by topping the casserole with the remaining shredded cheese. Use the back of a spoon to gently press all the ingredients down into an even layer, ensuring no dry pieces of bread are exposed on the surface. This step is crucial for a perfectly uniform and moist casserole.
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Cover the casserole dish tightly with aluminum foil and transfer it to the refrigerator. Allow it to chill overnight, or for a minimum of 4 hours. This chilling period is vital for the bread to fully absorb the egg mixture, leading to a superior texture and enhanced flavor profile once baked.
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When you are ready to bake, preheat your oven to 350°F (175°C). Place the covered casserole directly from the fridge into the preheated oven. Bake for approximately 45-60 minutes, or until the casserole is beautifully puffed up and completely set in the center (it should not be jiggly). For the last 10-15 minutes of baking, remove the foil to allow the top layer of cheese to become golden brown and bubbly.
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If desired, garnish the baked casserole with freshly chopped chives before serving. Let it rest for a few minutes to allow the flavors to settle, then slice and serve immediately while it’s wonderfully hot. Enjoy your magnificent homemade breakfast!
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Notes
- For the best texture and flavor, it is highly recommended to chill this casserole for at least 4 hours after assembly, or even better, overnight. This allows the bread to fully absorb the egg mixture, resulting in a perfectly moist and cohesive casserole. This make-ahead capability makes it an outstanding choice for stress-free holiday mornings and brunches, as you can prepare it well in advance.
- If you prefer a quicker preparation or wish to follow a more traditional approach, you can substitute the homemade mushroom gravy with a standard 10.5-ounce can of condensed cream of mushroom soup. For ease of spreading, gently warm the soup in a small saucepan or microwave until it reaches a more fluid consistency before spooning it evenly over the casserole layers.
- Feel free to customize this recipe by adding other vegetables like bell peppers, spinach, or sun-dried tomatoes. You can also experiment with different types of cheese or swap out the sausage for turkey sausage or even a plant-based alternative for dietary variations.
This recipe was originally published in December 2021 in partnership with Challenge Dairy, Inc. I extend my sincere gratitude for supporting partnerships with brands I truly love and believe in, as these collaborations make Completely Delicious possible. Rest assured, all opinions expressed are always 100% my own, ensuring authenticity and trust.