Mix yeast with flour. Warm milk with butter. Knead all the dough ingredients. Let rise for 30 minutes.
Peel and grate the potatoes. Quarter, core and grate the apples. Cut the onion into fine rings. Mix the ingredients, season with salt, pepper and nutmeg. Roll out the dough, place in a buttered springform pan (26 cm), pull the edge of the dough up 3 cm. Spread the filling on the dough.
Put the tin in the cold oven, bake the cake at 180 ° C for about 1 hour.
Grate cheese, mix with cream and egg. Season to taste with salt, pepper and nutmeg. After 30 minutes of baking time, place on the cake and sprinkle with caraway seeds. Finish baking the cake.