- 1/4 pound store-bought puff pastry, thawed
- 8 ounces (about 12 slices) bacon, cut crosswise into 1/2-inch strips
- 1 medium onion, halved and thinly sliced
- 3 large eggs
- 1/2 cup heavy cream
- Salt and fresh ground pepper
- 1 1/2 cups grated (4 ounces) Gruyere cheese
- Preheat oven to 400 degrees. On a lightly floured surface, roll pastry to 10-inch square (trim the edges with a paring knife). Place pastry into an 8-inch square baking pan, folding corners to fit. Prick bottom of dough with a fork.
- Heat a large skillet over medium-high heat. Add bacon; cook, stirring occasionally, until pieces start to brown, 4 to 5 minutes. Add onions; cook, stirring occasionally, until bacon is crisp and onions are lightly browned, 5 to 7 minutes. With a slotted spoon, transfer mixture to a plate; let cool slightly.
- Scatter onion mixture over pastry. In a small bowl, whisk eggs, cream, 1/4 teaspoon salt, and 1/8 teaspoon pepper. Pour egg mixture into pastry shell. Sprinkle Gruyere over top. Bake until filling is set and top is golden brown, about 40 minutes.
If the rolled-out dough becomes too soft to handle, briefly refrigerate it while you prepare the rest of the recipe. This casserole is an excellent dish to serve for brunch.