Description
Delight in these savory Caramelized Onion Tarts featuring flaky puff pastry topped with sweet, slow-cooked onions, fresh thyme, and melted Gruyère cheese. Perfect as an elegant appetizer or a light lunch paired with a crisp green salad, these French-inspired tarts combine rich flavors and a buttery crust for a crowd-pleasing dish.
Ingredients
Scale
Pastry
- 1 sheet puff pastry, thawed
Caramelized Onions
- 2 large yellow onions, thinly sliced
- 2 tablespoons unsalted butter
- 1 tablespoon olive oil
- 1 teaspoon fresh thyme leaves (or 1/2 teaspoon dried thyme)
- 1/4 teaspoon salt
- 1/4 teaspoon black pepper
- 1 teaspoon balsamic vinegar
Topping
- 1/2 cup shredded Gruyère cheese (or Swiss)
- 1 egg, beaten (for egg wash)
- Fresh thyme or microgreens for garnish (optional)
Instructions
- Preheat Oven: Preheat your oven to 400°F (200°C) to prepare for baking the tarts.
- Caramelize Onions: In a large skillet over medium-low heat, melt the butter with olive oil. Add thinly sliced onions, salt, and pepper. Cook slowly, stirring occasionally, for 25 to 30 minutes until the onions are deeply golden and caramelized.
- Add Thyme and Balsamic: During the last 5 minutes of cooking, stir in the thyme leaves and balsamic vinegar to enhance flavor.
- Prepare Puff Pastry: On a lightly floured surface, roll out the puff pastry sheet and cut it into 4 equal rectangles. Arrange the pieces on a parchment-lined baking sheet. Lightly score a 1/2-inch border around each rectangle’s edges and prick the centers with a fork to prevent puffing.
- Assemble Tarts: Evenly distribute the caramelized onions over the centers of each pastry rectangle. Sprinkle shredded Gruyère cheese on top. Brush the edges of each pastry with the beaten egg wash to achieve a golden finish.
- Bake: Bake the assembled tarts for 18 to 22 minutes or until the pastry is puffed up and golden brown.
- Garnish and Serve: Let the tarts cool slightly. Optionally, garnish with fresh thyme or microgreens and serve warm.
Notes
- These tarts make a wonderful appetizer, brunch item, or light lunch when paired with a green salad.
- Feel free to substitute Gruyère cheese with brie, goat cheese, or sharp white cheddar based on preference.
- Scoring around the edges and pricking the center helps control how the pastry puffs during baking.
