This breakfast casserole with sausage and veggies is my favorite way to kickstart the day with a plateful of delicious! It’s make-ahead-friendly, freezer-friendly, and loaded with vegetables, eggs, soft bread cubes, fresh herbs, and juicy breakfast sausage.
Breakfast casseroles are super flexible and perfect for feeding a crowd. If you’re looking for another easy recipe, check out my overnight slow cooker breakfast casserole. For something sweet, give this apple French toast casserole a try.
I love a good breakfast casserole. Today’s variation is a savory, flavor-loaded breakfast casserole with sausage, vegetables, and eggs, and it’s officially a new favorite. It’s very easy to put together and incredibly filling, like a meal in one since it’s packed with a rainbow of ingredients. Just look at all those delicious bites of golden bread, savory sausage, and veggies!
Why I Love This Breakfast Casserole Recipe
- Super satisfying. This sausage breakfast casserole is an all-in-one breakfast (dare I say lunch and even dinner!). It’s fully loaded with fluffy egg-soaked bread cubes, savory ground meat, fresh herbs, and a whole gamut of veggies. One serving is enough to fill you up.
- Easy to prep. You’ll need to pre-cook the meat and veggies for this casserole, but the prep time is minimal. You can even prepare the casserole ahead of time and bake it later!
- Flexible. Change up the ingredients in this breakfast casserole recipe any way you’d like. Choose your favorite ground sausage (or skip the meat if you’re vegetarian), add even more veggies, shredded cheese, and more. Just about anything goes.
- Crowd-friendly. This recipe is one of my favorite things to make for Christmas morning. Especially if we have family visiting, since it can feed a small army and then some! Otherwise, any leftovers store and freeze great.
Ingredients You’ll Need
This breakfast casserole recipe is very customizable, but I’ll get you started with some notes on the easy ingredients I use. You’ll find a printable ingredients list with the full recipe details in the recipe card below the post.
- Bread Cubes – Just like making French toast (or in this case, savory French toast), the best bread for this breakfast casserole is day-old, stale bread. I like to use crusty ciabatta and cut it into cubes.
- Olive Oil – Or another cooking oil, like avocado oil.
- Breakfast Sausage – Pick up a package of ground breakfast sausage, either pork, chicken, beef, or any kind that you prefer. Spicy chorizo is a good way to add a little heat. If you have sausages that come in links or patties, you can take them out of the casings or break them up.
- Vegetables – This can be just about any vegetables you’d like. I pack this breakfast casserole full of diced onion, bell peppers, zucchini, broccoli florets, and sliced cremini mushrooms.
- Garlic – Freshly minced. If you have garlic powder, substitute about ¼ teaspoon per fresh garlic clove instead.
- Butter – I like to cook with unsalted butter, but salted works here, too.
- Fresh Herbs – In addition to seasoning with salt and pepper, I’m all about the flavor of savory herbs like chopped fresh thyme, oregano, and parsley in this casserole. You can use basil, rosemary, or any herbs you’d like.
- Eggs – This recipe makes a sizeable breakfast casserole, so I use a whole dozen eggs. Lightly beat them before you start.
- Half-and-Half – You can also use heavy cream, whole milk, or a dairy-free alternative.
- Sour Cream – If you don’t have sour cream, Greek yogurt works well as a substitute.
How to Make a Breakfast Casserole With Sausage
There’s a little sautéing to do, but this is very quick and simple to assemble. You can use a single skillet and transfer each ingredient to the baking dish as it comes out of the pan. Easy! Follow the step-by-step with photos here:
- Prep the baking dish. First things first, butter up a 9×13” baking dish. Gather your bread cubes and spread them into the pan.
- Cook the sausage. Next, get ground sausage sizzling in a skillet with oil, breaking it up with a wooden spoon as it cooks. Once that’s browned, scoop the sausage out of the pan (use a slotted spoon) and straight into the baking dish.
- Sauté the veggies. Now, cook the diced onions and bell peppers, then add the zucchini, broccoli, and garlic. Sauté until everything is fork-tender, and layer the veggies over the bread and sausage.
- Sauté the mushrooms. Once the veggies have left the building (I mean, pan), sauté mushroom slices in butter with the herbs until they’re nicely browned. Afterward, move the mushrooms to the casserole dish, too.
- Blend. Meanwhile, blend or whisk up the eggs with half-and-half and sour cream. Season with salt and pepper, making sure it’s evenly mixed.
- Put it all together. All that’s left to do is pour the egg mixture over the contents of the casserole dish and give the ingredients a gentle toss to coat.
- Bake. Bake the breakfast casserole at 375ºF for 45 minutes, or until it’s set and golden on top. Rest the casserole outside the oven for 10 minutes afterward, then slice and serve!
Make-Ahead
You can pre-cook the ingredients and assemble this casserole up to 1 day ahead. It’s fine to let it soak in the fridge overnight! Cover the casserole tightly and refrigerate until you’re ready to bake the next day. If you’re baking cold from the fridge you’ll need to add 10 minutes or so to the cooking time.
Tips and Variations
- Pre-cook the ingredients. Don’t skip this step! While it does add to the prep time, pre-cooking the sausage and veggies is important. First, it ensures that everything is thoroughly cooked. And, secondly, it releases excess moisture that would otherwise find its way into the casserole and make it soggy.
- Swap out the sausage. You can replace the sausage in this breakfast casserole with another protein, like bacon, diced ham, shredded chicken, or even leftover Thanksgiving turkey.
- Change up the veggies. Other good vegetable choices for this recipe are asparagus and greens like spinach and kale. Remember to cook them first.
- Add potatoes. You can replace the bread chunks with cooked hash brown potatoes or leftover roasted potatoes for an even heartier breakfast.
- Make it cheesy. Sprinkle in shredded cheddar, crumbled feta, Gruyère, grated parmesan, or goat’s cheese.
What to Serve With Sausage Breakfast Casserole
This breakfast casserole with sausage is a full meal in one! Usually, I’ll serve it as-is next to my morning cortado, sometimes with a side of fresh fruit. That being said, a slice of casserole goes great with sides like cheesy hash browns and air fryer bacon, or pumpkin cinnamon rolls at brunch, and I’ll definitely be passing around mimosas if we have friends or family over. A cozy breakfast casserole is also one of my Christmas morning go-to’s. Serve it up while sipping on an eggnog latte!
Storing and Reheating Leftovers
- Refrigerate. The baked sausage breakfast casserole can be kept covered in the fridge for up to 4 days.
- Reheat. Warm slices in the microwave or in the oven until hot throughout.
- Freeze. You can freeze this casserole whole or in slices. Let it cool completely, and double-wrap it tightly with plastic wrap or store leftovers in an airtight container. Freeze for up to 3 months and thaw it in the fridge before reheating.
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- 5 slices day-old bread, I like ciabatta, cubed into 1-inch pieces
- 2 tablespoons olive oil, plus more, as needed
- 1 pound breakfast sausage
- 1 small red onion, diced
- 1 red bell pepper, chopped
- 1 small to medium zucchini, diced
- 1½ cups chopped broccoli
- 2 cloves garlic, minced
- 1½ tablespoons unsalted butter
- 8 ounces sliced cremini mushrooms
- 1½ teaspoons kosher salt, divided
- 1 tablespoon chopped fresh thyme
- 1 tablespoon chopped fresh oregano
- 1 tablespoon chopped fresh parsley
- 12 large eggs, beaten
- ½ cup half and half
- ¼ cup sour cream
- ½ teaspoon freshly ground black pepper
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Prep. Preheat the oven to 375°F and liberally grease a 9X13-inch casserole dish with butter. Spread the cubed bread over the bottom of the dish.
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Brown the sausage. Heat the olive oil in a large, heavy-bottomed skillet over medium-high heat. Add the sausage and saute until nicely caramelized and cooked through, breaking it apart with a wooden spoon as you go. Use a slotted spoon to transfer the cooked sausage to the baking dish.
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Saute the veggies. Add another 1 ½ tablespoons of olive oil to the skillet (only if the skillet looks dry), followed by the onion and bell pepper. Saute until the onion is translucent. Add the zucchini, broccoli, and garlic and saute for 4 to 5 minutes or until the veggies have softened. Transfer the contents of the skillet to the casserole dish with the sausage and cubed bread.
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Saute the mushrooms. Add the butter to the pan. Once the butter has melted, add the mushrooms and season with ½ teaspoon salt along with the thyme, oregano, and parsley. Saute until the mushrooms have browned nicely. Turn off the heat and transfer the mushrooms to the casserole dish.
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Blend. To a blender, add the eggs, half and half, sour cream, pepper, and remaining salt. Blend until well combined. You can also mix this with an electric mixer or by hand with a whisk.
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Put it all together. Pour the egg mixture over the contents of the casserole dish. Gently toss everything together in the casserole dish to make sure the bread cubes, sausage, and veggies are thoroughly coated in the egg mixture.
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Bake. Bake for 45 minutes or until the eggs have set.
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Rest and serve. Allow the breakfast casserole to rest for 10-15 minutes before slicing and serving.
Calories: 426kcal | Carbohydrates: 16g | Protein: 21g | Fat: 31g | Saturated Fat: 11g | Polyunsaturated Fat: 4g | Monounsaturated Fat: 13g | Trans Fat: 0.2g | Cholesterol: 302mg | Sodium: 996mg | Potassium: 593mg | Fiber: 2g | Sugar: 5g | Vitamin A: 1265IU | Vitamin C: 42mg | Calcium: 115mg | Iron: 3mg
Nutritional info is an estimate and provided as courtesy. Values may vary according to the ingredients and tools used. Please use your preferred nutritional calculator for more detailed info.