Warm the milk lukewarm. Mix flour, yeast and some salt. Mix with milk to a smooth dough. Cover and leave to rise in a warm place for about 30 minutes. Peel garlic and crush finely.
Peel onions and cut them into thin rings. Heat the oil in portions in a large frying pan. Fry the onions for 10-12 minutes while turning. Fry half of the garlic. Season and let cool off.
Knead the dough again and divide it into about 16 pieces. Roll out to thin flat cakes (approx. 15 cm Ø) on a lightly floured work surface. Place 4 flat cakes on a baking tray lined with baking paper.
Cheese crumbles. Wash herbs, chop. Stir crème fraiche, egg yolk and starch until smooth. Stir in remaining garlic and herbs, season. Spread some crème fraiche on each flat cake. Spread onions and cheese on top.
Bake the cakes one after the other in a hot oven (electric range: 225 °C/ convection oven: 200 °C/ gas: level 4) on the lowest rack for 10-12 minutes.