Sausage Breakfast Casserole

Breakfast casserole recipes check all the boxes. They're easy to put together, they serve a crowd, and most—including this sausage breakfast casserole—can even be assembled the night before and baked the next morning. If you’re looking to simplify busy mornings, add this to your must-make list!

This casserole is hearty and satisfying, loaded with savory browned sausage, hash browns, eggs, and a generous helping of cheddar cheese. Whip it up for your next breakfast, brunch, or breakfast-for-dinner!

What's the difference between a breakfast casserole and a frittata?

While they’re both delicious egg recipes, breakfast casseroles and frittatas (like this Caprese frittata) aren't the same. Frittatas are usually started on the stovetop in a skillet, then finished in the oven. Their texture is firmer and more similar to an omelet.

A breakfast casserole, on the other hand, is baked entirely in the oven. It tends to be creamier and richer, thanks to an egg-and-dairy custard base. While it can include many of the same mix-ins as a frittata, a casserole usually has a starchy layer—like bread or potatoes—that soaks up the custard and makes it feel heartier and more substantial.

Why is my breakfast casserole soggy?

In any egg-based breakfast casserole, extra moisture from the other ingredients can affect the final texture. To help prevent sogginess, sauté the vegetables before adding them to the egg mixture so they release excess moisture. If you're considering a different kind of cheese, choose a low-moisture variety (not fresh mozzarella or feta, for example). Pick something firm, like cheddar or pepper jack.

Should you cover sausage breakfast casserole while it bakes?

Yes, covering the casserole with foil while baking prevents it from drying out. This breakfast bake is covered for most of the time it's in the oven. Toward the end, you remove the foil, sprinkle the casserole with cheese, and increase the oven temperature. After another 15 minutes, it should be fully set with melted cheese and a golden top.

Can you make sausage breakfast casserole ahead of time?

Yes, this breakfast casserole can be assembled, covered, and refrigerated for up to one day before baking. Let it sit at room temperature while the oven preheats to knock off some of the chill.

How long does breakfast casserole last in the fridge?

Covered tightly, the baked casserole will stay good for up to 4 days in the refrigerator. Reheat individual portions in the microwave. For larger portions, cover the baking dish with foil and reheat in a 350-degree Fahrenheit oven for 15 to 20 minutes or until warmed through.

Can you freeze sausage breakfast casserole?

Yes! Bake the casserole and let it cool completely. Wrap the baking dish or any leftovers tightly in a layer of plastic wrap, followed by a layer of foil, then freeze for up to three months. Let the casserole thaw in the refrigerator overnight before reheating, covered, in a 350-degree Fahrenheit oven until warmed through.

What do you serve with sausage breakfast casserole?

With a hearty combination of sausage, eggs, vegetables, and potatoes, this breakfast casserole can certainly stand alone. But when you want a full spread, this simple fruit salad goes wonderfully with a breakfast casserole. And who could say no to a round of mimosas or Bloody Marys?

How to Make Sausage Breakfast Casserole

INGREDIENTS

• Butter: Use a little butter or nonstick cooking spray to grease the bottom and sides of your baking dish so nothing sticks.
• Breakfast sausage: You need one pound of sausage for this breakfast casserole. Use mild or spicy breakfast sausage, or even turkey sausage, depending on your preference.
• Bell pepper and onion: Vegetables add color and flavor, and make this a well-rounded morning meal. You can use any color bell pepper, and if you don't have green onion, finely diced yellow onion is a great swap. Want to pack in some extra greens? Throw in a handful of spinach or even fold in bite-size pieces of broccoli. Just be sure to sauté the vegetables first (as instructed in the recipe) to remove some moisture so you aren't left with a runny casserole.
• Eggs: Ten large eggs form the base of the casserole, binding everything together and giving it structure while staying soft and fluffy.
• Heavy cream: Cream makes the egg mixture creamy and luscious. You can use half-and-half instead, but the casserole won’t be quite as rich.
• Dijon mustard: Mustard is the unsung hero here. It adds subtle tang and extra depth that cuts through the richness of the casserole.
• Salt and pepper: A little kosher salt and black pepper go a long way in seasoning this dish. If you’re using table salt, you'll need a little less.
• Cheddar cheese: There's shredded cheese baked into this casserole and sprinkled on top to form a tasty golden crust. Sharp cheddar has the perfect amount of bite to balance this dish, but you can use monterey jack, colby jack, or pepper jack instead.
• Hash browns: Part of what makes this casserole so hearty and satisfying is the potatoes. There's no need to peel and chop your own; just grab a bag of shredded hash browns from your supermarket's freezer section! Frozen tater tots or diced potatoes can be used instead, just make sure to thaw them first.

STEP-BY-STEP INSTRUCTIONS

Brown the sausage in a skillet, breaking it up with a wooden spoon as it cooks. When it’s fully cooked and no pink is left, drain off most of the grease, but leave about 1 to 2 tablespoons in the pan. Add the bell pepper and the white and light green parts of the green onion, and save the dark green parts for later. Let the veggies cook in the sausage drippings until they soften, which adds a lot of flavor.

While the sausage and vegetables are cooking, whisk together the creamy custard with eggs, heavy cream, mustard, hot sauce, and seasonings. Once that's all combined, fold in most of the cheese, plus the hash browns and cooked sausage, peppers, and onions.

Scoop everything into a greased baking dish and cover it with foil. If you're making the casserole in advance, now is the time to place it in the fridge to bake later. If you've got a hungry crowd to feed now, go ahead and pop it into a 350-degree Fahrenheit oven for 50 minutes.

When your timer goes off, remove the foil and sprinkle on the rest of the shredded cheese. Crank up the heat to 400 degrees Fahrenheit so the cheese melts and the casserole gets golden on top. After another 10 to 15 minutes of baking, it should be fully set. If the center is still jiggly, return it to the oven for a few more minutes.

Let the casserole cool for 10 minutes, then top it with the green onion greens, slice, and dig in.

A full list of ingredients and directions can be found in the recipe below.