Ingredients
Method
Instructions
- Heat olive oil and butter in a pan over medium heat. Add the sliced onions and cook until soft and translucent. Sprinkle with sugar and continue cooking until the onions are golden brown and caramelized. Stir in the thyme leaves and season with salt and pepper. Set aside to cool.
- Roll out the thawed puff pastry on a lightly floured surface. Transfer it to a parchment-lined baking sheet. Using a sharp knife, score a border about 1 inch from the edge of the pastry, being careful not to cut all the way through.
- Spread the caramelized onions evenly over the pastry, staying within the scored border. Arrange the beefsteak tomato slices on top of the onions, slightly overlapping them. Season the tomatoes with salt and pepper.
- Brush the edges of the pastry with the beaten egg. Bake in a preheated oven at 375°F (190°C) for 25-30 minutes, or until the pastry is golden brown and puffed.
- Allow the tart to cool slightly before slicing. Garnish with additional thyme leaves if desired. Serve warm or at room temperature.
Notes
For extra flavor, sprinkle grated Parmesan cheese over the caramelized onions before adding the tomatoes. To prevent a soggy crust, pat the tomato slices dry with a paper towel before placing them on the tart. This tart can be served as a main dish with a side salad or as an appetizer for a larger meal.
