Mix all ingredients for the dough and roll out very thinly on baking paper.
Cut the pumpkin into 2-3 mm thin slices and mix with the oil and chilli flakes. Cut the leek and onion into thin rings. Remove the tomatoes from the oil and cut into small pieces.
Preheat the oven to 250 °.
Spread the crème fraîche on the dough, season with rosemary, salt and pepper. Then spread the pumpkin slices, the leek and onion rings, tomatoes on top. Pay attention to the optics, so that the eye also benefits, I play with the colors of the individual ingredients. Now bake crispy on a baking sheet in the middle of the oven for about 15-20 minutes.
If you want, you can serve the tarte flambée with a fresh lamb`s lettuce. It is enough to just serve the salad with dressing (e.g. lemon and olive oil dressing). The focus is on the tarte flambée anyway.