Sausage, Caramelized Onion, Mushroom and Gruyere Strata
This savory strata -- a layered breakfast casserole -- features bread, sausage, onions mushrooms and gruyere baked in a rich custard. A perennial crowd-pleaser, it can be prepared in advance and simply popped in the oven an hour before serving.
Equipment
- rimmed baking sheet
- large saute pan or skillet
- 9" x 13" baking dish
Ingredients
- 8 cups (16 oz.) day old French bread, cut in 1” cubes
- 1 pound Italian or breakfast sausage
- 2 tablespoons unsalted butter plus more for the baking dish
- 1 tablespoon extra-virgin olive oil
- 1 large Spanish onion diced
- 8 ounces cremini mushrooms trimmed and sliced (dice if large)
- Kosher salt and freshly ground pepper
- 2 teaspoons minced fresh thyme
- 10 large eggs
- 2 cups whole milk
- 1 cup heavy cream
- 1 tablespoon Dijon mustard
- 1 teaspoon Kosher salt
- ½ teaspoon freshly ground pepper
- ⅛ teaspoon freshly grated nutmeg
- 2 cups grated Gruyere cheese divided
Instructions
- Preheat the oven to 325°F. Place bread cubes on a baking sheet and toast until toasted golden brown on both sides, about 10 minutes. Remove and reserve.
- Meanwhile, in a large sauté pan, cook the sausage over medium- high heat, breaking up with the back of a wooden spoon, until browned and crumbled, about 8-10 minutes. Remove sausage to drain on a paper towel. Drain fat from skillet.
- To the same skillet, over medium heat, add butter and olive oil. Add the onions, and cook stirring occasionally until softened, about 5 minutes. Add the sliced mushrooms, sprinkle with salt and pepper, and continue cooking, stirring occasionally until onions are lightly browned and caramelized and mushrooms are starting to brown, about 15 minutes. Add thyme and sauté for two more minutes. Remove from the heat and reserve.
- In a large bowl, whisk together eggs, milk, cream, mustard, 1 teaspoon salt, ½ teaspoon pepper and nutmeg. Butter a 9-by-13-inch baking dish.
- Arrange half of the toasted bread cubes over the bottom of the baking dish. Top evenly with half the browned sausage, followed by half the onion/mushroom mixture and ¾ cup cheese. Repeat with remaining bread cubes, sausage, onion/muffin mixture and ¾ cup cheese.
- Pour egg mixture over contents of baking dish and press down lightly to make sure it is submerged. Cover with foil or plastic wrap and refrigerate for 8 hours or overnight.
- Preheat oven to 350°F. Bake the strata, uncovered, until it is golden brown on top, puffed and custard is firm when the baking dish is shaken, about 50 minutes. Sprinkle with remaining ½ cup cheese during the last 10 minutes of baking. Let cool before serving.