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The Caramelized Onion & Gruyère Tart is a sublime dish that embodies the essence of savory sophistication. With its flaky crust and rich filling, this tart is a delightful fusion of flavors that elevates any meal, whether served as an appetizer, main course, or a brunch centerpiece. The caramelized onions lend a sweet, savory depth, while the Gruyère cheese adds a creamy, nutty richness, making each bite a comforting experience.

Caramelized Onion & Gruyère Tart

Discover the deliciousness of a Caramelized Onion & Gruyère Tart, a dish that’s sure to impress! With its flaky puff pastry crust and rich filling of sweet caramelized onions and creamy Gruyère cheese, this tart elevates any gathering. Perfect as an appetizer or centerpiece for brunch, it balances savory and sweet in each bite. Learn the techniques for caramelizing onions and enjoy a comforting culinary experience that combines elegance with home-cooked warmth!
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Ingredients
  

1 sheet of puff pastry, thawed

4 large onions, thinly sliced (preferably yellow or sweet onions)

3 tablespoons unsalted butter

1 tablespoon olive oil

1 teaspoon sugar

½ teaspoon salt

½ teaspoon black pepper

1 teaspoon fresh thyme leaves (or ½ teaspoon dried thyme)

1 cup grated Gruyère cheese

1 large egg

2 tablespoons heavy cream

1 tablespoon Dijon mustard (optional)

Fresh parsley, chopped (for garnish)

Instructions
 

Preheat the Oven: Preheat your oven to 400°F (200°C).

    Caramelize the Onions: In a large skillet, heat the butter and olive oil over medium heat. Add the sliced onions, sugar, salt, and pepper. Stir occasionally for about 20-25 minutes until the onions are golden brown and caramelized. Add the thyme during the last few minutes of cooking. Set aside to cool slightly.

      Prepare the Puff Pastry: Roll out the puff pastry on a lightly floured surface to fit into a 9-inch tart pan. Place the pastry in the tart pan, trimming any excess. Prick the bottom with a fork to prevent bubbling.

        Blind Bake (Optional): For a crisper base, you can blind bake the pastry. Line it with parchment paper and fill with pie weights or dried beans. Bake for 10 minutes, then remove from the oven and remove the weights. Allow it to cool slightly.

          Mix the Custard: In a bowl, whisk together the egg, heavy cream, and Dijon mustard (if using) until well combined.

            Assemble the Tart: Spread the caramelized onions evenly over the puff pastry base. Sprinkle the grated Gruyère cheese on top. Pour the egg and cream mixture evenly over the cheese and onions.

              Bake the Tart: Bake in the preheated oven for 25-30 minutes, or until the tart is golden and puffed, and the top is set.

                Garnish and Serve: Let the tart cool for a few minutes before slicing. Garnish with fresh parsley and serve warm or at room temperature.

                  Prep Time, Total Time, Servings: 20 minutes | 1 hour | 8 servings