Easy Make-Ahead Breakfast Casserole
A delightful make-ahead breakfast casserole with golden bread, savory sausage, vibrant vegetables, and creamy cheese, perfect for busy mornings or weekend brunches.
Ingredients
Main Ingredients
- 1 tablespoon olive oil A healthy fat that enhances flavor.
- 1 lb breakfast sausage The savory heart of the dish.
- 1 small yellow onion, diced Brings a sweet aroma.
- 8 cups day-old bread cubes (sourdough, French bread, or challah) The star of the casserole, for soft texture.
- 10 large eggs The key ingredient that binds everything.
- 2.5 cups whole milk Enriches the mixture with creaminess.
- 1 tablespoon Dijon mustard Adds a zesty kick.
- 1 teaspoon garlic powder For aromatic flavor.
- 3/4 teaspoon kosher salt Enhances overall flavor.
- 1/2 teaspoon black pepper Adds subtle spice.
- 2 cups shredded sharp cheddar cheese, divided For melty goodness.
- 2 tablespoons chopped fresh parsley or green onion, optional For garnishing.
Instructions
Preparation
- Heat the olive oil in a large skillet over medium heat.
- Add the breakfast sausage, diced onion, and red bell pepper. Sauté for about 8-10 minutes until the sausage is browned and the vegetables are tender.
- Drain excess grease and allow the mixture to cool for about 10 minutes.
- Grease a 9x13-inch casserole dish well.
- Spread the day-old bread cubes evenly in the dish, then distribute the cooled sausage mixture over the bread.
Making Custard
- In a large mixing bowl, whisk together the eggs, whole milk, Dijon mustard, garlic powder, kosher salt, and black pepper until smooth.
Assembling and Refrigerating
- Sprinkle 1.5 cups of shredded cheddar over the sausage and bread.
- Pour the egg mixture over the entire dish, pressing down gently to help the bread absorb.
- Cover with plastic wrap or foil and refrigerate for at least 1 hour, preferably overnight.
Baking
- Preheat the oven to 350°F (175°C).
- Sprinkle the remaining 1/2 cup of cheddar cheese on top.
- Cover loosely with foil and bake for 30 minutes.
- Remove foil and continue to bake for an additional 20-25 minutes until golden brown.
- Let the casserole rest for 10 minutes before slicing. Garnish if desired and serve warm.
Notes
For the best results, use day-old bread for better absorption and let the casserole sit overnight for optimal flavor. Avoid using fresh bread.