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 until the onions are golden brown and caramelized, 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 bottom of the pastry with a fork to prevent it from puffing up during baking.
- Spread the caramelized onions evenly over the puff pastry. 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 puff pastry with the beaten egg wash. Bake in the preheated oven for 25-30 minutes, or until the pastry is golden brown and the cheese is melted and bubbly.
- Allow the tart to cool for a few minutes before slicing and serving. Garnish with additional fresh thyme leaves if desired.
Notes
Choose ripe tomatoes for the best flavor. Use a sharp knife to slice the tomatoes evenly. To avoid a soggy crust, blind bake the puff pastry for 10 minutes before adding the toppings. Experiment with different cheeses like Gruyère or goat cheese for a unique flavor. A drizzle of balsamic glaze before serving can enhance the sweetness of the caramelized onions and tomatoes.
