Description
A delicious Caramelized Onion Tart featuring sweet, slowly cooked onions and rich Gruyère cheese on a flaky puff pastry base, garnished with fresh thyme. This savory tart makes a perfect appetizer or light meal, combining buttery caramelized onions with the nutty flavor of Gruyère.
Ingredients
Scale
For the Tart
- 2 large onions, thinly sliced
- 2 tablespoons butter
- 1 sheet puff pastry (thawed if frozen)
- ½ cup shredded Gruyère cheese
- Fresh thyme, for garnish
Instructions
- Prepare the Onions: Peel and thinly slice two large onions. This will ensure they caramelize evenly and develop their natural sweetness during cooking.
- Caramelize the Onions: Heat 2 tablespoons of butter in a skillet over medium-low heat. Add the sliced onions and cook slowly, stirring occasionally, for about 30-40 minutes until deep golden brown and caramelized. Patience during this step is key as it develops the flavor.
- Preheat the Oven: While the onions are caramelizing, preheat your oven to 400°F (200°C) to prepare for baking the tart.
- Prepare the Puff Pastry: Roll out the thawed sheet of puff pastry on a baking sheet lined with parchment paper. You can score a border around the edges if desired, about 1 inch from the edge, to allow the edges to puff up nicely.
- Assemble the Tart: Spread the caramelized onions evenly over the puff pastry within the scored border. Sprinkle ½ cup shredded Gruyère cheese evenly on top of the onions for a rich, melted topping.
- Bake the Tart: Place the tart in the preheated oven and bake for 15-20 minutes or until the puff pastry is golden and fully cooked, and the cheese is bubbly and slightly browned.
- Garnish and Serve: Remove the tart from the oven and let it cool slightly. Garnish with fresh thyme leaves before slicing and serving. Enjoy warm or at room temperature.
Notes
- Be patient during caramelization to avoid burning the onions and to develop the best flavor.
- Gruyère cheese adds a nutty, creamy flavor, but you can substitute with Swiss or mozzarella if desired.
- This tart is best enjoyed fresh but can be reheated gently in a low oven.
- For a crispier crust, chill the puff pastry before baking.
- Experiment with adding a splash of balsamic vinegar to the onions while caramelizing for extra depth.
