Golden Caramelized Onion & Gruyère Puff Pastry Tart Recipe
This Golden Caramelized Onion & Gruyère Puff Pastry Tart is a delicious French-inspired appetizer featuring sweet, jammy caramelized onions paired with nutty Gruyère cheese atop a flaky puff pastry crust. Perfectly baked to a golden brown, this tart offers a harmonious blend of savory flavors and buttery textures, making it an ideal dish for entertaining or a satisfying snack.
- Prep Time: 15 minutes
- Cook Time: 45 minutes
- Total Time: 60 minutes
- Yield: 6 servings 1x
- Category: Appetizer
- Method: Baking
- Cuisine: French
- Diet: Vegetarian
Ingredients
Scale
Puff Pastry Base
- 1 sheet puff pastry, thawed (about 10x10 inches)
- 1 egg, beaten (for brushing)
- 1 tbsp Dijon mustard (optional, for flavor depth)
Caramelized Onions
- 3 large yellow onions, thinly sliced
- 2 tbsp butter
- 1 tbsp olive oil
- 1 tsp sugar
- Salt, to taste
- 1 tsp fresh thyme leaves (plus more for garnish)
Cheese Mixture
- 1 cup (100 g) shredded Gruyère cheese
- ¼ cup (60 ml) heavy cream
- 1 egg
- ½ tsp black pepper
Instructions
- Caramelize the Onions: In a large skillet, melt butter with olive oil over medium heat. Add the thinly sliced onions, sugar, and a pinch of salt. Cook slowly, stirring often, for 25–30 minutes until the onions become golden brown and jammy, then stir in the fresh thyme leaves. Set aside to cool slightly.
- Prepare the Oven and Pastry: Preheat your oven to 400°F (200°C). Place the thawed puff pastry sheet onto a parchment-lined baking sheet. Using a knife, score a 1-inch border around the edges carefully without cutting through the dough. Lightly prick the inner section with a fork to prevent excessive puffing during baking. Brush the edges with the beaten egg to enhance browning.
- Pre-Bake the Pastry: Bake the prepared puff pastry in the preheated oven for about 10 minutes or until the edges turn lightly golden. This step ensures a crisp crust that can hold the toppings.
- Make the Cheese Mixture: In a mixing bowl, whisk together the heavy cream, egg, black pepper, and shredded Gruyère cheese until fully combined.
- Assemble the Tart: If using, spread the Dijon mustard evenly over the pre-baked pastry base within the scored border. Pour the cheese mixture on top, spreading it evenly inside the border. Then, generously layer the caramelized onions over the cheese mixture.
- Final Bake: Return the tart to the oven and bake for an additional 15–18 minutes, or until the tart is puffed up and golden brown.
- Garnish and Serve: Remove from the oven and sprinkle fresh thyme leaves and a pinch of sea salt over the tart. Slice into squares and serve warm or at room temperature for the best flavor.
Notes
- For a vegetarian option, ensure the Dijon mustard used is vegetarian-friendly.
- This tart can be served as an elegant appetizer or a main dish when paired with a fresh salad.
- To enhance the flavor, use high-quality Gruyère cheese and fresh thyme.
- Allow the tart to cool slightly before slicing to prevent the filling from spilling.
Keywords: caramelized onion tart, Gruyère cheese tart, puff pastry tart, French appetizer, baked cheese tart, savory tart recipe
