Ingredients
Method
Instructions
- Heat the olive oil and butter in a large skillet over medium heat. Add the sliced onions and cook, stirring occasionally, until they begin to soften. Sprinkle with sugar and continue cooking, stirring frequently, until the onions are golden brown and caramelized. This should take about 20-25 minutes. Stir in the fresh thyme leaves and season with salt and pepper. Set aside to cool.
- Preheat your oven to 375°F (190°C). Roll out the thawed puff pastry on a lightly floured surface to fit your tart pan. Transfer the pastry to the pan and trim any excess edges. Prick the base of the pastry with a fork to prevent it from puffing up during baking.
- Spread the caramelized onions evenly over the puff pastry base. Arrange the sliced beefsteak tomatoes on top of the onions, slightly overlapping them. Sprinkle the shredded mozzarella and grated Parmesan cheese over the tomatoes. Brush the edges of the pastry with the beaten egg to create a golden crust.
- Place the tart in the preheated oven and bake for 25-30 minutes, or until the pastry is golden brown and the cheese is melted and bubbly. Remove from the oven and let it cool slightly before serving.
Notes
Choose ripe tomatoes for the best flavor. Slice the tomatoes evenly to ensure they cook uniformly and look beautiful on the tart. To avoid a soggy crust, pat the tomato slices dry with a paper towel before placing them on the tart. Garnish the tart with additional fresh thyme or basil leaves before serving for an extra burst of flavor.
