Easy Make-Ahead Breakfast Casserole (Print version)
A hearty overnight breakfast casserole with sausage, eggs, cheese, and bread that bakes into clean, golden slices.
# Ingredients:
For the filling
01 -
1 tablespoon olive oil
02 -
1 lb (450 g) breakfast sausage
03 -
1 small yellow onion, diced
04 -
1 red bell pepper, diced
For the casserole
05 -
8 cups (about 300 g) day-old bread cubes, from sourdough, French bread, or challah
06 -
10 large eggs
07 -
2 1/2 cups (600 ml) whole milk
08 -
1 tablespoon Dijon mustard
09 -
1 teaspoon garlic powder
10 -
3/4 teaspoon kosher salt
11 -
1/2 teaspoon black pepper
12 -
2 cups (225 g) shredded sharp cheddar cheese, divided
13 -
2 tablespoons chopped fresh parsley or green onion, optional
# Instructions:
01 -
Heat the olive oil in a large skillet over medium heat. Add the sausage, onion, and bell pepper. Cook for 8-10 minutes, breaking up the meat, until the sausage is browned and the vegetables are soft. Drain excess grease and cool for 10 minutes.
02 -
Grease a 9x13-inch baking dish. Spread the bread cubes evenly in the dish, then scatter the cooled sausage mixture over the bread.
03 -
In a large bowl, whisk the eggs, milk, Dijon mustard, garlic powder, salt, and black pepper until smooth and evenly blended.
04 -
Sprinkle 1 1/2 cups of the cheddar over the bread and sausage. Pour the egg mixture evenly over the top, then press gently so the bread starts to absorb the custard.
05 -
Cover the dish tightly and refrigerate for at least 1 hour or up to overnight. Overnight gives the bread the best texture.
06 -
Heat the oven to 350 F. Sprinkle the remaining 1/2 cup cheddar on top. Bake covered with foil for 30 minutes, then uncover and bake 20-25 minutes more, until golden and the center reaches 160 F.
07 -
Let the casserole rest for 10 minutes before slicing. Garnish with parsley or green onion if using, then serve warm.
# Good to know:
01 -
Assemble up to 24 hours ahead and bake straight from the refrigerator.
02 -
If baking from cold, add 5-10 minutes as needed for the center to set.
03 -
Use sturdy bread, not very soft sandwich bread, for the best texture.