Description
This easy and customizable Egg Bake Overnight Breakfast Casserole combines savory chicken sausage, fresh vegetables, eggs, and cheese into a delicious, protein-packed dish perfect for feeding a crowd. It can be baked immediately, made ahead up to 24 hours, or frozen for convenient meal prep and entertaining.
Ingredients
Sausage
- 10 to 12 ounces (280-340g) chicken sausage, casing removed
- Olive oil, as needed for cooking
Vegetables
- 2 cloves garlic, minced
- 3 cups (90g) fresh spinach
- 2 large bell peppers, diced
- ½ medium yellow onion, diced
- Salt and pepper to taste
Egg Mixture
- 12 large eggs
- ½ cup (120g) milk (any type)
- ½ cup (56g) shredded cheese (any flavor), divided
Instructions
- Prepare baking dish: Spray a 7 x 11 or 9 x 13-inch casserole dish with non-stick spray and set aside. If baking immediately, preheat oven to 375ºF (191ºC).
- Cook sausage: In a large skillet over medium heat, brown the chicken sausage, breaking it into pieces. If using fully cooked sausage, browning slightly is optional but recommended for flavor. Once browned, spoon sausage evenly into the prepared casserole dish.
- Sauté vegetables: Add olive oil to the skillet if needed. Sauté minced garlic, spinach, diced bell peppers, and diced onion over medium heat until vegetables are tender and spinach wilts, about 6-7 minutes. Season with salt and pepper during the last minute.
- Combine sausage and vegetables: Remove skillet from heat and add the cooked vegetable mixture to the sausage in the casserole dish. Stir roughly to distribute ingredients evenly.
- Mix eggs and pour: In a medium bowl, whisk together eggs, milk, and ¼ cup of shredded cheese. Pour this mixture evenly over the sausage and vegetables in the casserole dish. Sprinkle the remaining ¼ cup shredded cheese and additional salt and pepper on top. Cover and refrigerate up to 24 hours if not baking immediately.
- Bake: When ready to bake, preheat oven to 375ºF (191ºC) if not already done. Bake the casserole for about 45 minutes or until the edges are golden brown and eggs are set. Let cool at least 15 minutes before serving.
- Store and reheat: Refrigerate leftovers up to 5 days and reheat individual portions in the microwave. The baked casserole can also be frozen for up to 2 months. To reheat from frozen, thaw overnight in the refrigerator and bake at 350ºF (177ºC) for approximately 20 minutes until heated through.
- Freezing unbaked casserole: Freeze the unbaked casserole tightly wrapped in plastic wrap and aluminum foil for up to 2 months. Thaw overnight in refrigerator before baking as directed.
Notes
- You can customize the cheese flavor according to preference, such as cheddar, mozzarella, or pepper jack.
- Use fully cooked sausage for quicker prep; browning adds extra flavor but is optional.
- Vegetable choices can be varied or added to, such as mushrooms or zucchini.
- Allow casserole to cool before refrigerating or freezing to maintain texture.
- Reheat gently to avoid drying out the eggs.
- Perfect for meal prep, brunch gatherings, or breakfast-for-dinner occasions.
