01 - Preheat the oven to 400°F. Line a baking sheet with parchment paper.
02 - Roll out the puff pastry on a lightly floured surface to smooth the seams. Cut into 6 equal rectangles or circles and place on the prepared baking sheet.
03 - Using a small knife, lightly score a 1/2-inch border around each tartlet (do not cut all the way through). Prick the centers with a fork.
04 - Spread a thin layer of goat cheese inside the border of each tartlet. Sprinkle with grated Parmesan.
05 - Arrange tomato slices and red onion (if using) over the cheese. Drizzle with olive oil and scatter with basil and thyme. Season with salt and pepper.
06 - Brush the pastry borders with beaten egg.
07 - Bake for 20–25 minutes, or until the pastry is puffed and golden and the tomatoes are slightly caramelized.
08 - Cool for a few minutes. Garnish with extra basil and serve warm or at room temperature.