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 thyme leaves and season with salt and pepper. Set aside to cool.
- Preheat your oven to 400°F (200°C). Roll out the puff pastry sheet on a lightly floured surface to a thickness of about 1/8 inch. Transfer the pastry to a parchment-lined baking sheet.
- Spread the caramelized onions evenly over the puff pastry, leaving a 1-inch border around the edges. Arrange the beefsteak tomato slices on top of the onions, slightly overlapping if necessary. Fold the edges of the pastry over the tomatoes to create a rustic tart shape.
- Brush the edges of the pastry with the beaten egg. Bake in the preheated oven for 25-30 minutes, or until the pastry is golden brown and crisp.
- Allow the tart to cool slightly before slicing. Serve warm or at room temperature, garnished with additional thyme leaves if desired.
Notes
Choose ripe but firm beefsteak tomatoes for the best flavor. Slice the tomatoes evenly to ensure they cook uniformly. To avoid a soggy bottom, blind-bake the puff pastry for 10 minutes before adding the toppings. For an extra layer of flavor, sprinkle some grated Parmesan or crumbled feta cheese over the caramelized onions before adding the tomatoes.
