Ingredients
Scale
- 2 large yellow onions, thinly sliced
- 2 tablespoons butter (or olive oil for dairy-free)
- 1 tablespoon olive oil (for cooking)
- 1 tablespoon brown sugar
- 1 teaspoon balsamic vinegar (optional)
- 1 sheet (about 8 oz) puff pastry, thawed
- 4 ounces goat cheese, room temperature
- 1 large egg, beaten (for egg wash)
- 1 teaspoon fresh thyme leaves (or 1/2 teaspoon dried thyme)
- 1/4 teaspoon kosher salt (adjust to taste)
- 1/8 teaspoon black pepper, freshly ground
- 1 teaspoon honey (optional drizzle)
- 1 cup arugula (for serving, optional)
- Extra thyme sprigs (for garnish, optional)
Instructions
- Preheat the oven to 400°F (200°C) and line a baking sheet with parchment paper.
- Heat a large skillet over medium heat and add the butter and olive oil.
- Add the sliced onions and a pinch of salt. Cook, stirring occasionally, until onions soften, about 10 minutes.
- Sprinkle the brown sugar over the onions, stir, and continue to cook until deep golden brown and jammy, about 10–15 more minutes.
- Stir in the balsamic vinegar and thyme, cook for 1 more minute, then remove from heat and let cool slightly.
- Unfold the puff pastry on a lightly floured surface and roll gently to smooth the seams. Cut into 4 equal rectangles (or 8 smaller squares).
- Transfer pastry pieces to the baking sheet. Using a sharp knife, score a 1/2-inch border around each rectangle without cutting all the way through.
- Spread a thin layer of goat cheese inside each border, leaving the edges clear.
- Spoon the caramelized onions evenly over the goat cheese, pressing lightly to secure.
- Brush the exposed pastry borders with the beaten egg for a golden finish.
- Bake until pastry is puffed and golden, about 15–20 minutes, rotating the pan halfway through.
- Remove tarts from the oven, drizzle lightly with honey if using, and top with arugula or extra thyme before serving.
Notes
Cook the onions low and slow to avoid burning. Keep puff pastry cold until just before baking to ensure maximum flakiness.
- Prep Time: 15 minutes
- Cook Time: 25 minutes
- Category: Appetizer
- Method: Baking
- Cuisine: French
- Diet: Vegetarian