Description
This comforting Breakfast Casserole features buttery croissants, savory sweet Italian sausage, fresh scallions, and aromatic sage baked in a creamy custard with Gruyère cheese. Prepared ahead and slow baked to golden perfection, it’s perfect for a hearty brunch or family breakfast, delivering rich flavors and a satisfying texture.
Ingredients
For the Casserole Base
- 1-2 tablespoons butter, softened
- 1 pound croissants (about 5 to 7), split in half lengthwise
- 1 tablespoon vegetable oil
- 1 bunch scallions (6 to 7), white and light green parts thinly sliced, greens reserved
- 3/4 pound sweet Italian sausage, casings removed
- 2 teaspoons fresh sage, finely chopped
For the Egg Mixture
- 8 large eggs, at room temperature
- 3 cups whole milk
- 1 cup heavy cream
- 1 1/2 cups Gruyère cheese, grated (reserve 1/2 cup for topping)
- 1 1/4 teaspoons salt
- 1 teaspoon black pepper
For Garnish
- 1/2 cup Gruyère cheese, grated
- 1 tablespoon fresh sage, finely chopped
- Reserved green parts of scallions
Instructions
- Grease Baking Dish: Use 1-2 tablespoons of softened butter to generously grease a 9×13 inch baking dish. Set it aside. Preheat your oven to 350ºF (177ºC).
- Toast Croissants: Arrange croissant halves cut side up on a large baking sheet. Bake for 2 to 4 minutes until golden brown, then remove and let cool until manageable. Tear the croissants into large bite-sized pieces.
- Cook Sausage: Heat 1 tablespoon vegetable oil in a skillet over medium-high heat. Add the sweet Italian sausage, cooking and crumbling it until well browned and cooked through, about 6-8 minutes.
- Add Scallions: Stir in the sliced white and light green scallion parts into the sausage mixture. Continue cooking until scallions are softened.
- Incorporate Sage and Cool: Mix in 2 teaspoons of finely chopped fresh sage. Remove the skillet from heat and let the sausage mixture cool for 7-10 minutes to avoid cooking the eggs later.
- Combine Croissants and Sausage Mixture: In a large bowl, toss together the toasted croissant pieces and cooled sausage mixture to evenly distribute flavors.
- Prepare Egg Custard: In a separate large mixing bowl, whisk together 8 large eggs, 3 cups whole milk, 1 cup heavy cream, 1 1/2 cups grated Gruyère, 1 1/4 teaspoons salt, and 1 teaspoon black pepper until fully combined and smooth.
- Assemble Casserole: Pour the croissant and sausage mixture into the buttered baking dish and spread evenly. Pour the egg mixture over the top, gently pressing down the croissants so they absorb the liquid well.
- Refrigerate: Cover the assembled casserole tightly with plastic cling wrap. Refrigerate for at least 4 hours or overnight to let the custard soak thoroughly into the croissants and flavors meld.
- Preheat Oven for Baking: When ready to bake, preheat your oven again to 350ºF (177ºC).
- Bake Casserole: Remove the plastic wrap. Sprinkle the remaining 1/2 cup Gruyère cheese on top of the casserole. Bake uncovered for about 45 minutes or until the top is golden brown and the center is firm to the touch. Remove from oven and let sit for 10 minutes before serving.
- Garnish and Serve: Top the casserole with the reserved scallion greens and 1 tablespoon of chopped fresh sage for a fresh accent. Serve warm and enjoy your flavorful breakfast casserole.
Notes
- For best results, prepare the casserole the night before to allow the bread to soak in the custard fully.
- Using day-old croissants can enhance texture as they absorb the custard better.
- You can substitute sweet Italian sausage with spicy Italian sausage for a kick.
- Gruyère provides a nutty flavor, but Swiss or cheddar cheese can be used as alternatives.
- Make sure the eggs are at room temperature for a smoother custard.
- Prep Time: 15 minutes
- Cook Time: 50 minutes
- Category: Breakfast
- Method: Baking
- Cuisine: American