Description

This Sausage and Sage Croissant Breakfast Casserole is a savory, custardy bake perfect for brunch or a hearty breakfast. Featuring flaky croissants soaked in a rich egg custard with browned sweet Italian sausage, fresh sage, scallions, and melty Gruyère cheese, this casserole offers a delightful blend of textures and flavors. Prepared ahead and baked until golden, it makes a comforting and crowd-pleasing dish.

Ingredients

Scale

Butter and Oil

1-2 tablespoons butter, softened
1 tablespoon vegetable oil

Bakery

1 pound croissants (about 5 to 7), split in half lengthwise

Meat

3/4 pound sweet Italian sausage, casings removed

Produce

1 bunch scallions (6 to 7), white and light green parts thinly sliced, greens reserved
2 teaspoons fresh sage, finely chopped (plus 1 tablespoon for garnish)

Dairy

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)

Seasonings

1 1/4 teaspoons salt
1 teaspoon black pepper

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Instructions

Grease Baking Dish: Use 1-2 tablespoons of softened butter to generously grease a 9×13 inch baking dish. Set it aside and 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 flavor, use fresh sage and high-quality Gruyère cheese.
Allowing the casserole to soak in the fridge overnight helps the croissants absorb the custard fully, resulting in a creamy texture.
Use room temperature eggs to ensure a smooth custard.
This casserole can be reheated in the oven at 350ºF for 15-20 minutes before serving.
For a spicier version, substitute sweet Italian sausage with hot Italian sausage.