If you're looking for the ultimate make-ahead breakfast or brunch recipe, this Sausage Hash Brown Breakfast Casserole is it. It's loaded with hash browns, savory sausage, sautéed mushrooms, melty cheese, and fluffy eggs. It's everything you could want in a breakfast bake, especially one that's so simple to make!
I've been making some version of a hash brown egg casserole for years, especially around the holidays. This one has become my go-to because it's not only easy to make, but it's also packed with flavor and holds up really well for leftovers. It's also endlessly adaptable depending on what you have on hand!
Why You'll Love This Sausage Hash Brown Breakfast Casserole
- It's perfect for holidays or weekend brunch: I make this every for Christmas Day breakfast since I can make it the day before, then just pop it in the oven while we're opening gifts.
- It's make-ahead: Assemble it the night before and just pop it in the oven when you're ready!
- It's hearty and filling: With sausage, mushrooms, hash browns, eggs, and cheese, it's a complete meal in one dish.
- It's easily customizable: You can easily swap ingredients to fit your preferences or what you have in the fridge. Don't like mushrooms? Leave them out! Prefer chorizo to breakfast sausage? Easy swap. You get the idea.
- Leftovers are delicious when reheated: It tastes just as good the next day, making it a great choice for meal prep or quick breakfasts during the week.
Ingredients You'll Need
Here's what you'll need to make this sausage hash brown breakfast casserole:
- Hash Browns: Shredded hash brown potatoes form the potato "base" of this recipe. Frozen works great (and there's no need to thaw!), but you can also use refrigerated or freshly grated potatoes.
- Breakfast Sausage: Use pork breakfast sausage, and you can go with mild, hot, or a combination. Turkey sausage or even chicken sausage are great alternatives.
- Mushrooms: Sautéed mushrooms add that rich umami flavor. White button or cremini mushrooms (aka baby bellas) work best.
- Eggs: These bind everything together and give the casserole its classic eggy texture.
- Milk: Whole milk or 2% gives the egg mixture a creamy, custardy texture.
- Cheddar Cheese: Sharp cheddar adds a ton of flavor! You could swap this for Monterey Jack or Pepper Jack, or do a combination. Grate your own cheese if you can, as it melts better and adds more flavor than pre-shredded.
- Cooking Oil: Used for sautéing the mushrooms and crisping the hash browns.
- Green Onions: Optional, but they add a nice pop of color and freshness on top.
- Coarse Salt & Freshly Ground Black Pepper: Salt = Flavor!
Step-by-Step Instructions
This hearty breakfast bake comes together in just a few simple steps. Here's how to layer everything for the perfect texture:
1. Sauté the Mushrooms
Heat 1 tablespoon of vegetable oil in a large skillet over high heat. Add the sliced mushrooms and cook until they release their moisture and turn golden brown. Set them aside.
2. Brown the Sausage
In the same skillet, cook the breakfast sausage over medium heat until it's fully browned with no pink remaining. Drain any excess grease and set the sausage aside.
3. Crisp the Hash Browns
Add the remaining tablespoon of oil to the skillet and cook the hash browns until they're golden and crispy on both sides. Season them with salt and pepper while they cook.
4. Mix the Egg Custard
In a large mixing bowl, whisk together the eggs, milk, shredded cheddar cheese, and a pinch of coarse salt. This is the creamy base that holds the casserole together.
5. Assemble the Casserole
Grease a 13x9-inch baking dish. Spread the hash browns evenly across the bottom. Layer the cooked sausage on top, followed by the sautéed mushrooms. Carefully pour the egg mixture over everything, making sure the cheese is evenly distributed.
6. Bake
Cover the dish with foil and bake at 350°F for 20 minutes. Remove the foil and continue baking for another 20-25 minutes, or until the eggs are set and the top is lightly golden.
7. Rest and Garnish
Let the hash brown breakfast casserole rest for 10 minutes before slicing (this will allow the slices to firm up so they don't fall apart when you're plating them). Top with chopped green onions and serve.
Variations & Substitutions
One of the best things about this sausage hash brown breakfast casserole is how easy it is to customize. Here are some ideas for how to make it your own:
- Make it vegetarian: Skip the sausage and add more veggies like sautéed spinach, bell peppers, zucchini, or roasted sweet potatoes.
- Use a different protein: Swap the sausage for crumbled bacon, diced ham, or plant-based meat alternatives.
- Change up the cheese: Try mozzarella, pepper jack for a spicy kick, or a Mexican blend.
- Add some spice: Stir in diced jalapeños, green chiles, or a few dashes of hot sauce.
- Try different mushrooms: Shiitake or a gourmet blend would be great choices. You can also omit them entirely!
- Make it dairy-free: Use plant-based cheese and an unsweetened non-dairy milk like almond or oat.
This breakfast casserole is endlessly adaptable, so mix and match ingredients to make it your own!
How to Make it Ahead
This make-ahead breakfast casserole is a lifesaver for busy mornings, especially around the holidays or when hosting brunch.
- To Prep Ahead: Assemble the entire casserole as directed, but don't bake it. Cover the dish tightly with foil or plastic wrap and refrigerate overnight. In the morning, let it sit at room temperature for about 30 minutes while the oven preheats, then bake it as directed.
This is a great option for overnight breakfast casserole fans. You'll wake up to a ready-to-bake meal, which is such a great feeling!
Storage & Reheating
This hash brown breakfast casserole holds up beautifully, making it perfect for leftovers or meal prep.
How to Store
- Refrigerator: Let the casserole cool completely, then cover tightly with foil or transfer to an airtight container. Store in the refrigerator for up to 4-5 days.
- Freezer: Not recommended for this recipe. Because of the eggs and dairy, freezing can affect the texture and cause separation when thawed.
How to Reheat
- Whole Casserole: Cover with foil and reheat in a 350°F oven for 15-20 minutes, or until warmed through.
- Individual Portions: Microwave on a plate in 30-second intervals, stirring or rotating between each, until heated through.
Can I freeze this breakfast casserole?
Yes, this casserole freezes very well!
To freeze after baking: Let the casserole cool completely, then cut it into portions. Wrap each piece tightly in plastic wrap and place in a freezer-safe bag or container. Reheat individual servings in the microwave or oven until warmed through.
What to Serve With It
This sausage hash brown breakfast casserole is hearty enough to stand on its own, but it pairs particularly well with the dishes below:
- Fresh Fruit Salad: A mix of berries, melon, and citrus is a nice contrast to the rich casserole.
- Buttery Croissants or Biscuits: Perfect for soaking up any cheesy, eggy goodness left on your plate.
- Cinnamon Rolls or Sticky Buns: Adds a sweet contrast.
- Yogurt Parfaits: Layer Greek yogurt with granola and fresh fruit for a lighter option.
- Maple-Glazed Bacon: Salty and sweet, it's a crowd-pleaser alongside any egg dish.
- Orange Juice or a Mimosa Bar: This is especially fun if you're serving brunch for a group!
Frequently Asked Questions
Can I use fresh potatoes instead of frozen hash browns?
Yes! Just peel and grate russet potatoes, then squeeze out as much moisture as possible using a clean kitchen towel or paper towels. Too much moisture can make the casserole soggy.
Can I freeze this breakfast casserole?
Yes, it freezes well and you can freeze individual portions for an easy breakfast any day of the week. See the freezing instructions above. ⬆️
How far in advance can I assemble it?
You can fully assemble the casserole up to 24 hours in advance. Just cover it tightly and refrigerate. Let it sit at room temperature for about 30 minutes before baking.
What kind of sausage should I use?
Any ground breakfast sausage works: mild, hot, or even turkey sausage. You can also use Italian sausage, chorizo, or any other kind of cooked sausage.
Can I make it without mushrooms?
Absolutely! If you're not a fan of mushrooms, just leave them out or replace them with diced bell peppers, spinach, or another veggie you love.
Is this casserole gluten-free?
Yes, as long as your hash browns and sausage are labeled gluten-free. Always double-check ingredient labels if you're cooking for someone with a gluten intolerance.
If you're a fan of easy, savory breakfasts like this casserole, you'll love my egg bake with cottage cheese: it's light, packed with protein, and ridiculously simple to throw together. Another go-to in my kitchen is this breakfast hash brown quiche, which combines a crispy potato crust with a creamy egg filling that always gets rave reviews. For something with a little kick, try the smoky, spicy chipotle baked eggs that are perfect with crusty bread on the side. And if you like your breakfast all in one skillet, this skillet breakfast with bacon and potatoes is an easy and hearty choice that never disappoints!
Sausage Hash Brown Breakfast Casserole
Sausage Hash Brown Casserole – hash brown potatoes, sausage, mushrooms eggs & cheese – perfect for making ahead and feeding a large crowd for breakfast or brunch.
Ingredients
- 2 tablespoons avocado oil, divided (any cooking oil with a high smoke point)
- 16 oz mushrooms, thickly sliced
- 32 oz breakfast sausage (mild, hot, or a combination)
- 16–20 oz shredded hash brown potatoes (frozen or fresh)
- 10 large eggs
- 2 cups milk (whole or 2%)
- 2 cups shredded cheddar cheese
- Coarse salt and freshly ground black pepper, to taste
- ¼ cup chopped green onions (optional, for garnish)
Instructions
- Preheat the oven to 350°F and grease a 13x9-inch baking dish.
- Sauté the mushrooms: Heat 1 tablespoon of oil in a large skillet over high heat. Add the mushrooms and cook until they're nicely browned and all moisture has evaporated. Set aside.
- Cook the sausage: In the same skillet, brown the sausage over medium heat until fully cooked. Drain the excess grease and set aside.
- Crisp the hash browns: Add the remaining tablespoon of oil to the skillet. Spread the hash browns in an even layer and cook until golden on both sides. Season well with salt and pepper.
- Make the egg mixture: In a large bowl, whisk together the eggs, milk, shredded cheese, and 1 teaspoon salt until well combined.
- Assemble the casserole: Layer the hash browns evenly in the bottom of the baking dish. Top with the sausage, then the mushrooms. Pour the egg mixture evenly over the top.
- Bake: Cover with foil and bake for 20 minutes. Remove foil and bake an additional 20–25 minutes, or until the eggs are fully set and the top is lightly golden.
- Rest and serve: Let the casserole rest for 10 minutes before slicing. Garnish with chopped green onions, if desired.
Nutrition Information:
Yield: 10 Serving Size: 1Amount Per Serving: Calories: 987Total Fat: 96gSaturated Fat: 38gTrans Fat: 1gUnsaturated Fat: 45gCholesterol: 90mgSodium: 346mgCarbohydrates: 69gFiber: 16gSugar: 10gProtein: 34g
This data was provided and calculated by Nutritionix.
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Tara says
Can you do this one the night before
Kristy Bernardo says
You can assemble it the night before and bake it in the morning. Add a few minutes of baking time if it goes in cold from the fridge.
Michelle | A Dish of Daily Life says
I love breakfast casseroles, and especially ones that are hearty like this! Your picture looks so good, I wish it could just jump off the screen and right on to my plate!
Kristy Bernardo says
Thanks, Michelle! Happy Holidays!