For the ham flambé, prepare the dough according to instructions and place on a baking sheet lined with parchment paper.
Grate raclette cheese, pluck or chop thyme. Stir everything into creme fraiche and season with salt, pepper and lemon juice.
Spread the mixture on the dough, leaving out the edges. Preheat oven to 220°C.
Clean and wash the leeks, cut into thin rings and sprinkle over the tarte flambée.
Bake for 15 minutes and sprinkle with finely diced ham. Serve the ham tarte flambée while it is still hot.