Description
This Overnight Croissant Breakfast Casserole is a savory and satisfying dish perfect for a make-ahead brunch or breakfast. Layers of flaky butter croissants, browned breakfast sausage, sautéed onions, and melted cheddar cheese are soaked overnight in a rich egg and milk mixture, then baked to golden perfection. Finished with a creamy homemade sausage gravy, this comforting casserole brings together delicious flavors and a delightful texture that’s sure to please a crowd.
Ingredients
Scale
Sausage and Vegetable
- 1 tbsp olive oil
- 1 small onion, peeled and chopped
- 1 lb breakfast sausage, mild flavor
Casserole Base
- 4 large butter croissants or 8 small croissants
- 1 cup shredded cheddar cheese
Egg Mixture
- 6 large eggs
- 1/2 cup heavy whipping cream
- 1/2 cup whole milk (from the 3 cups total, divided)
- 1/2 tsp dry mustard powder
- 1/2 tsp salt (plus additional for the gravy to taste)
- 1/2 tsp black pepper (plus additional for the gravy to taste)
- 1/4 tsp paprika
- 1/4 tsp garlic powder
Gravy
- 2 tbsp butter
- 3 tbsp all-purpose flour
- 2 1/2 cups whole milk (remaining from the 3 cups total)
Instructions
- Sauté Onions: Heat the olive oil in a skillet over medium heat. Add the chopped onions and cook until they become soft and translucent, about 5 minutes.
- Cook Sausage: Add the breakfast sausage to the skillet with onions and cook until the sausage is browned all over. Drain excess fat, reserving some for the gravy, and allow the mixture to cool slightly.
- Combine Casserole Ingredients: Tear the croissants into bite-sized pieces and place them in a large bowl. Add the cooked sausage and onions along with the shredded cheddar cheese. Gently mix to combine.
- Assemble Casserole: Grease a 9×13-inch baking dish. Spread the croissant, sausage, and cheese mixture evenly in the dish.
- Prepare Egg Mixture: In a medium bowl, whisk together the eggs, heavy whipping cream, 1/2 cup of whole milk, dry mustard powder, salt, black pepper, paprika, and garlic powder until smooth.
- Soak and Refrigerate: Pour the egg mixture evenly over the croissant mixture in the baking dish. Cover with plastic wrap or a lid and refrigerate overnight to allow the croissants to soak up the custard.
- Bake Casserole: The next day, preheat your oven to 350°F (175°C). Remove the casserole from the fridge and bake uncovered for 35 to 45 minutes, until the top is golden brown and the custard is set.
- Make Gravy: While the casserole bakes, prepare the gravy. In a saucepan, melt butter with the reserved sausage fat over medium heat. Stir in the flour and cook, stirring constantly, for about 2 minutes to form a roux. Gradually whisk in the remaining 2 1/2 cups of milk, continuing to whisk until the mixture thickens and is smooth. Season with salt and black pepper to taste.
- Serve: Once the casserole is baked, serve it hot with the creamy sausage gravy on the side for pouring over individual portions.
Notes
- Using day-old croissants enhances texture as they absorb the custard better.
- Feel free to substitute cheddar with a different cheese like Gruyère or Monterey Jack for a variation in flavor.
- For a spicier kick, use spicy breakfast sausage or add cayenne pepper to the egg mixture.
- Make sure to cover and refrigerate overnight to allow the casserole to set properly.
- Gravy can be prepared ahead and reheated when ready to serve.
