Description
A rich and elegant caramelized onion and Gruyère tart with a flaky puff pastry crust buttery, savory, and deeply flavorful, perfect for brunches, appetizers, or a cozy dinner party centerpiece.
Ingredients
1 sheet puff pastry, thawed
2 tbsp unsalted butter
2 tbsp olive oil
3 large yellow onions, thinly sliced
1/2 tsp salt
1/2 tsp sugar
1 tsp fresh thyme leaves (or 1/2 tsp dried thyme)
1 tsp balsamic vinegar
1 cup shredded Gruyère cheese
1/4 cup grated Parmesan cheese
1 egg, beaten (for egg wash)
Fresh thyme sprigs, for garnish (optional)
Instructions
1. Preheat oven to 400°F (200°C) and line a baking sheet with parchment paper.
2. In a large skillet, melt butter and olive oil over medium-low heat. Add onions, salt, sugar, and thyme.
3. Cook slowly, stirring often, for 25–30 minutes until onions are deeply golden and caramelized.
4. Stir in balsamic vinegar and cook for 1 minute more. Remove from heat and let cool slightly.
5. Roll puff pastry onto the baking sheet and lightly score a 1-inch border around the edges (don’t cut through).
6. Brush the border with egg wash.
7. Sprinkle Gruyère and Parmesan cheeses evenly within the border.
8. Spread caramelized onions over the cheese layer.
9. Bake for 20–25 minutes, until pastry is puffed and golden.
10. Garnish with thyme sprigs before serving warm or at room temperature.
Notes
Add a sprinkle of crumbled bacon or prosciutto for extra richness.
Pairs beautifully with a crisp green salad or a glass of white wine.
Can be served as an appetizer, brunch dish, or light main course.
- Prep Time: 15 mins
- Cook Time: 35 mins
- Category: Appetizer
- Method: Baked
- Cuisine: French
Nutrition
- Serving Size: 1 slice
- Calories: 310
- Sugar: 5g
- Sodium: 310mg
- Fat: 22g
- Saturated Fat: 11g
- Unsaturated Fat: 10g
- Trans Fat: 0g
- Carbohydrates: 20g
- Fiber: 1g
- Protein: 9g
- Cholesterol: 55mg
Keywords: caramelized onion tart, gruyère tart, puff pastry appetizer, French tart, savory tart, onion and cheese tart