Crumble the yeast and mix with sugar until the yeast becomes liquid. Put flour, 1/4 tsp salt, 2 tbsp oil and 175 ml lukewarm water into a bowl. Add the mixed yeast and immediately knead into a smooth dough using the dough hooks of the hand mixer. Cover the dough and let it rise in a warm place for about 30 minutes.
Wash the thyme, dab dry and chop the leaves coarsely. Mix crème fraîche and 2/3 of the thyme, season with salt and pepper. Clean the turnips, peel them and cut them into very thin slices. Cut cheese into slices
Heat 1 tablespoon of oil in a frying pan. Fry the turnips in it for 2-3 minutes. Season with a little salt and remove. Halve the dough. Roll out half of the dough on a floured work surface in a very thin oval shape. Place the dough on a baking tray lined with baking paper. Spread half of the crème fraîche thinly on the base, then cover with half of the turnips and the cheese. Sprinkle with some pepper and thyme
Bake the tarte flambée in a preheated oven (electric cooker: 250 °C/ convection oven: 225 °C/ gas: see manufacturer) for 10-12 minutes until golden brown. Process and bake the other half of the dough and topping in the same way. Sprinkle each tarte flambée with 1-2 tbsp. olive oil and serve
Waiting time approx. 15 minutes