Preheat the oven to 200 degrees. Wash the tomatoes and cut into slices approx. 0.5 cm thick. Provide.
Place the puff pastry on a baking sheet, shape the edges and prick with a fork. Brush the bottom with mustard. Spread the tomato sauce on the mustard. Scatter breadcrumbs on top. Put on the tomato slices and season with pepper, salt and herbs of Provence. Baste generously with olive oil and bake for 25-30 minutes.