Description
This Caramelized Onion Tart with Gruyere and Thyme is a savory French-inspired appetizer or light meal featuring a flaky pie crust topped with sweet, deeply caramelized onions, fragrant thyme, and creamy Gruyere cheese. The tart combines rich flavors and textures, perfect for entertaining or a cozy dinner.
Ingredients
Scale
Crust
- 1 pie crust, preferably homemade (blind baked)
Filling
- 4 large onions, sliced into ¼-inch rounds
- 1 tablespoon sugar
- ½ teaspoon kosher salt
- 1½ tablespoons balsamic vinegar
- 2 tablespoons fresh thyme, chopped (or 2 teaspoons dried thyme)
- ¼ teaspoon freshly ground black pepper
- ¼ cup heavy cream
- 1 cup Gruyere cheese, grated
Instructions
- Preheat Oven: Set your oven to 375°F (190°C) to preheat while you prepare the filling.
- Blind Bake Pie Crust: Roll out the pie crust into a tart pan with a removable bottom. Prick the base with a fork, line it with parchment paper, and fill with pie weights or dried beans. Bake for about 15 minutes until set but not browned. Remove weights and parchments and set crust aside.
- Caramelize Onions: Heat a large skillet over medium heat. Add sliced onions, sugar, and kosher salt. Cook, stirring frequently, until onions are soft and golden brown, about 25 to 30 minutes. Stir in balsamic vinegar, thyme, and pepper and cook for an additional 2 minutes to meld flavors.
- Assemble Tart: Spread the caramelized onion mixture evenly over the blind-baked pie crust. Drizzle the heavy cream over the onions, then sprinkle the grated Gruyere cheese evenly on top.
- Bake Tart: Place the tart in the oven and bake for 25 to 30 minutes or until the Gruyere is melted, bubbly, and golden brown.
- Cool and Serve: Remove tart from oven and let cool for 10 minutes before removing from tart pan. Slice and serve warm or at room temperature.
Notes
- Blind baking the crust ensures the tart base stays crisp and does not get soggy from the wet filling.
- Caramelizing onions slowly over low-medium heat develops their natural sweetness and flavor complexity.
- Gruyere can be substituted with Emmental or Fontina cheese for a slightly different flavor profile.
- Fresh thyme is recommended but dried thyme can be used if fresh is unavailable.
- Serve this tart as an appetizer, side dish, or a light vegetarian main course.
