Looking for the perfect breakfast casserole to start your day? This savory, protein-packed dish is loaded with sausage, eggs, roasted sweet potatoes, mushrooms, bell peppers, and cheddar cheese for the ultimate morning meal. Whether you’re making it for a holiday brunch, meal prep, or a weekend family breakfast, this one-pan recipe is easy, filling, and absolutely delicious!
With a balance of protein, fiber, and flavor, this Breakfast Casserole is a crowd-pleaser that’s simple to customize. Plus, you can make it ahead of time, so all you have to do is pop it in the oven in the morning!
Why You’ll Love This Breakfast Casserole
✅ Make-Ahead Friendly – Perfect for meal prep or holiday breakfasts.
✅ Packed with Protein & Veggies – A nutritious and satisfying meal.
✅ One-Pan & Easy to Prepare – No mess, minimal cleanup!
✅ Customizable – Add different meats, cheeses, or veggies to make it your own.
✅ Great for Feeding a Crowd – Serves 12 people, making it ideal for gatherings.
What Makes This Breakfast Casserole So Good?
🍠 Roasted Sweet Potatoes – Adds natural sweetness and a crispy texture.
🥚 Fluffy Egg Base – Holds everything together while staying light and tender.
🧀 Melted Cheddar Cheese – A rich, creamy topping for extra flavor.
🍄 Savory Mushrooms & Peppers – Adds depth and freshness.
🌿 Perfect Blend of Seasonings – Garlic, onion, and oregano create a well-balanced flavor.
Ingredients You’ll Need
This wholesome breakfast casserole is made with simple, real-food ingredients:
For the Roasted Sweet Potatoes
- 1 medium/large sweet potato – Peeled and chopped into ½-inch cubes (about 3 cups).
- 1 tablespoon olive oil – For roasting.
- ½ teaspoon chili powder – Adds warmth.
- ¼ teaspoon salt – Enhances flavor.
- ⅛ teaspoon black pepper – Mild spice.
For the Casserole Filling
- 1 pound ground pork breakfast sausage – Crumbled.
- 8 ounces cremini mushrooms – Chopped.
- 1 red bell pepper – Diced.
- 6 green onions – White and light green parts chopped (divided).
- 1 cup shredded sharp cheddar cheese – Divided.
For the Egg Mixture
- 12 large eggs – The base of the casserole.
- 1 cup whole milk – Adds richness and creaminess.
- ½ teaspoon garlic powder – Boosts flavor.
- ½ teaspoon onion powder – Adds depth.
- ½ teaspoon dried oregano – A mild herbaceous touch.
- ¼ teaspoon salt & ¼ teaspoon black pepper – For seasoning.
💡 Want to add more flavor? Try smoked paprika, cayenne, or fresh herbs!
How to Make a Breakfast Casserole
This one-pan meal comes together in a few easy steps:
Step 1: Roast the Sweet Potatoes
- Preheat oven to 425°F (218°C).
- Line a rimmed baking sheet with parchment paper.
- In a large mixing bowl, toss sweet potatoes with olive oil, chili powder, salt, and pepper.
- Spread in a single layer and roast for 12 minutes.
- Flip, then continue roasting for 8-10 more minutes, until golden brown.
- Reduce oven temperature to 350°F (175°C).
💡 Roasting sweet potatoes adds a slightly crisp texture and caramelized flavor!
Step 2: Cook the Sausage & Veggies
- While the sweet potatoes roast, heat a large skillet over medium heat.
- Add breakfast sausage, breaking it up as it cooks.
- After 2-3 minutes, stir in chopped mushrooms and diced bell peppers.
- Cook until the sausage is fully browned, then drain excess grease.
💡 Using a leaner protein like turkey sausage? Add a little olive oil to prevent sticking!
Step 3: Prepare the Egg Mixture
- Lightly grease a 9×13-inch baking dish.
- In a large bowl, whisk together:
- Eggs
- Milk
- Garlic powder, onion powder, oregano, salt, and black pepper
💡 For extra creaminess, replace ¼ cup milk with heavy cream!
Step 4: Assemble the Casserole
- Stir in the roasted sweet potatoes, cooked sausage mixture, ⅔ of the green onions, and ⅔ of the shredded cheddar cheese.
- Pour the mixture into the prepared baking dish.
- Sprinkle remaining green onions and cheese on top.
💡 For a golden brown top, add an extra layer of cheese before baking!
Step 5: Bake Until Set
- Bake at 350°F (175°C) for 35-45 minutes, until the center is set and the edges are golden brown.
- Let rest for 5 minutes, then slice and serve warm.
💡 For a firmer texture, bake 5 minutes longer—for a softer texture, bake 5 minutes less!
Make-Ahead & Storage Tips
🥡 Make-Ahead: Assemble the casserole the night before, cover, and refrigerate. Bake in the morning!
❄️ Freeze: Cool completely, then wrap in foil and freeze for up to 2 months.
🔥 Reheat: Warm slices in a 350°F oven for 10-15 minutes or microwave for 30 seconds.
💡 If freezing, slice into portions first for quick, grab-and-go breakfasts!
Ways to Customize This Breakfast Casserole
🥓 Add Crispy Bacon – Cooked, crumbled bacon adds a smoky crunch.
🧀 Try a Different Cheese – Swap cheddar for pepper jack, Swiss, or feta.
🍄 Make It Vegetarian – Replace sausage with extra veggies, black beans, or tofu.
🌶 Make It Spicy – Add jalapeños, cayenne, or hot sauce for a kick.
🥑 Serve with Avocado – A creamy, healthy topping that pairs perfectly.
💡 For a low-carb version, skip the potatoes and add more veggies!
What to Serve with Breakfast Casserole
🥖 Crusty Bread or Biscuits – Perfect for scooping up every bite.
🥗 Fresh Fruit Salad – Lightens up the meal.
🥓 Extra Crispy Bacon or Sausage – For even more protein.
☕ Hot Coffee or Fresh Juice – The best pairing for a breakfast feast.
💡 Turn leftovers into breakfast sandwiches with toast or English muffins!
FAQs About Breakfast Casserole
Q: Can I make this dairy-free?
A: Yes! Use unsweetened almond milk and skip the cheese or use a dairy-free alternative.
Q: Can I make this in a slow cooker?
A: Yes! Cook on LOW for 6-7 hours or HIGH for 3-4 hours.
Q: Can I use regular potatoes instead of sweet potatoes?
A: Absolutely! Russet or Yukon Gold potatoes work great—just dice them small.
Final Thoughts
This Breakfast Casserole is easy, hearty, and packed with protein and veggies, making it the perfect make-ahead meal for busy mornings. Whether you’re meal prepping, hosting brunch, or just want a delicious, satisfying breakfast, this dish is a must-try!
Try this easy casserole today, and enjoy a flavor-packed start to your day! 🍳🥔✨
Short version
Breakfast Casserole
Ingredients
For the Sweet Potatoes:
- 1 medium/large sweet potato peeled (if desired) and chopped into ½-inch cubes (about 3 cups cubed)
- 1 tablespoon olive oil
- ½ teaspoon chili powder
- ¼ teaspoon salt
- ⅛ teaspoon black pepper
Remaining Casserole Ingredients:
- 1 pound ground pork breakfast sausage not links
- 8 ounces cremini mushrooms chopped
- 1 red bell pepper diced
- 12 large eggs
- 1 cup milk whole milk used
- ½ teaspoon garlic powder
- ½ teaspoon onion powder
- ½ teaspoon dried oregano
- ¼ teaspoon salt
- ¼ teaspoon black pepper
- 6 green onions white and light green parts only, chopped (divided)
- 1 cup shredded sharp cheddar cheese 4 ounces, divided
Instructions
- Roast Sweet Potatoes: Preheat the oven to 425°F. Line a rimmed baking sheet with parchment paper.
- In a large mixing bowl, toss the chopped sweet potatoes with olive oil, chili powder, salt, and pepper until evenly coated. Spread them out in a single layer on the baking sheet.
- Bake for 12 minutes, then toss/flip and continue baking for 8-10 more minutes, until soft in the center and golden brown on the edges. Wipe out the mixing bowl and set it aside for the egg mixture.
- Reduce oven temperature to 350°F.
- Brown the Sausage & Sauté the Veggies: While the sweet potatoes roast, heat a large skillet over medium heat. Add the sausage and cook, crumbling, for 2-3 minutes.
- Add the chopped mushrooms and diced bell peppers, stirring occasionally, and cook until the sausage is browned and fully cooked. Remove from heat and drain excess grease.
- Prepare the Egg Mixture: Grease a 9×13-inch baking dish.
- In the large mixing bowl, whisk together the eggs, milk, garlic powder, onion powder, dried oregano, salt, and pepper.
- Stir in the roasted sweet potatoes, cooked sausage, mushrooms, and bell peppers, along with ⅔ of the green onions and ⅔ of the shredded cheese. Pour the mixture into the greased baking dish and sprinkle the remaining green onions and shredded cheddar on top.
- Bake at 350°F for 35-45 minutes, until the edges are golden brown and the eggs are set in the center.
- Let the casserole rest for 5 minutes before slicing and serving.
Notes
