Crumble the yeast and dissolve in 1/8 l lukewarm water. Put 300 g flour, 1 pinch of salt, egg and 3 tablespoons of oil in a bowl. Add the dissolved yeast and knead with the dough hooks of the mixer to a smooth dough.
Cover and leave to rise in a warm place for about 45 minutes.
Peel and wash the potatoes, slice or cut them into very thin slices. Cover and cook in boiling salted water for 2-3 minutes. Drain and dab dry.
Line two baking trays with baking paper. Cut the dough in half and roll out round (approx. 25 cm Ø) on a little flour. Place them on the baking trays and let them rise covered for about 20 minutes.
Mix cream cheese and sour cream. Season with salt and pepper. Wash the rosemary, dab dry and remove the needles.
Preheat oven (electric cooker: 200°C/ circulating air: 175°C/ gas: level 3). Spread pizzas with cream cheese and cover with potatoes. Sprinkle with rosemary and sea salt. Sprinkle each with 1 tablespoon of oil. Bake one after the other in a hot oven for 20-25 minutes.