A savory tart featuring golden caramelized onions, flaky pastry, and creamy cheese for a flavorful bite.
# What You Need:
→ Pastry
01 - 1 sheet frozen puff pastry, thawed (approx. 8.8 oz)
→ Onions
02 - 3 large yellow onions, thinly sliced
03 - 2 tbsp unsalted butter
04 - 1 tbsp olive oil
05 - 1 tsp granulated sugar
06 - 1/2 tsp salt
07 - 1/4 tsp freshly ground black pepper
→ Filling and Topping
08 - 1/2 cup crème fraîche or sour cream (120 ml)
09 - 1 tsp Dijon mustard
10 - 1/2 cup grated Gruyère cheese (2 oz)
11 - 1 tsp fresh thyme leaves or 1/2 tsp dried thyme
12 - Optional: 1 tbsp chopped fresh chives, for garnish
# Directions:
01 - Preheat the oven to 400°F. Line a baking sheet with parchment paper.
02 - In a large skillet over medium heat, melt butter with olive oil. Add sliced onions, sugar, salt, and pepper. Cook, stirring frequently, until onions are deeply golden and caramelized, about 25 to 30 minutes.
03 - On a lightly floured surface, roll out puff pastry to a 12-inch square or circle. Transfer to the prepared baking sheet.
04 - In a small bowl, combine crème fraîche and Dijon mustard. Spread evenly over pastry, leaving a 1-inch border around the edges.
05 - Sprinkle half of the grated Gruyère over the crème mixture. Distribute caramelized onions on top. Sprinkle thyme leaves, then finish with remaining Gruyère.
06 - Fold pastry edges gently over the filling to create a rustic border.
07 - Bake in the preheated oven for 20 to 25 minutes, or until pastry is golden and crisp. Allow to cool slightly before slicing.
08 - Garnish with fresh chopped chives if desired. Serve warm or at room temperature.
