Easy Overnight Breakfast Casserole
This make-ahead breakfast casserole combines eggs, breakfast sausage, bread, bell peppers, onion, and plenty of melted cheese. Assemble it the night before, refrigerate, and bake in the morning for a warm and hearty breakfast.
Servings: 10
Calories: 390kcal
Ingredients
- 1 pound breakfast sausage
- 10 large eggs
- 2 cups whole milk
- 1 teaspoon Dijon mustard
- 1 teaspoon salt
- ½ teaspoon black pepper
- ½ teaspoon garlic powder
- 6 cups cubed day-old bread
- 2 cups shredded cheddar cheese
- ½ cup shredded Monterey Jack cheese
- ½ cup diced bell pepper
- ¼ cup finely diced onion
- 2 tablespoons chopped fresh parsley
Instructions
- Cook the sausage: Heat a large skillet over medium heat. Add the breakfast sausage and cook until browned and fully cooked, breaking it into small pieces. Drain excess grease and set aside.
- Make the egg mixture: In a large bowl, whisk together the eggs, milk, Dijon mustard, salt, black pepper, and garlic powder.
- Assemble: Lightly grease a 9 × 13-inch baking dish. Spread the cubed bread evenly in the dish. Top with cooked sausage, bell pepper, onion, cheddar, and Monterey Jack cheese.
- Add eggs: Pour the egg mixture evenly over the casserole. Gently press the bread down so it absorbs the liquid. Sprinkle parsley over the top.
- Refrigerate: Cover tightly and refrigerate for at least 6 hours, preferably overnight.
- Preheat: The next morning, remove the casserole from the refrigerator while the oven preheats to 350°F (175°C).
- Bake: Cover with foil and bake for 30 minutes. Remove the foil and bake for another 20–25 minutes, or until the center is set and the top is golden.
- Rest and serve: Let the casserole rest for about 10 minutes before slicing and serving.
Notes
- Day-old bread works best because it absorbs the egg mixture without becoming overly soft.
- Assemble the casserole up to 24 hours ahead and keep it refrigerated.
- Let the chilled casserole sit at room temperature briefly while the oven preheats.
- The center should be fully set before serving.
- Add spinach, mushrooms, tomatoes, or jalapeños for different variations.
Nutrition
- Calories: 390 kcal
- Carbohydrates: 20 g
- Protein: 22 g
- Fat: 26 g
- Saturated Fat: 11 g
- Cholesterol: 225 mg
- Sodium: 760 mg
- Fiber: 1 g
- Sugar: 3 g