Crumble the yeast and mix with sugar until the yeast becomes liquid. (This saves the pre-dough.) Put flour, 1/4 teaspoon salt, oil and 175 ml lukewarm water into a bowl. Add mixed yeast and knead immediately to a smooth dough. Cover the dough and let it rise in a warm place for about 30 minutes
Season sour cream with some salt and pepper
Line baking tray with baking paper. Halve the dough. Put 1 half on a baking tray and roll out very thin oval. Spread half of the sour cream on the bottom, sprinkle half of the ham cubes on top. Bake in the preheated oven on the lower shelf (electric oven: 250 °C/ convection oven: 225 °C/ gas: level 5) for 10-12 minutes
In the meantime, wash, clean and shake dry the rocket. Process remaining dough and topping in the same way. Take the tarte flambée out of the oven and bake the 2nd tarte flambée in the same way. Cover the tarte flambée with rocket
Waiting time approx. 30 minutes