Clean mushrooms, unscrew stalks and chop finely. Peel onion and garlic and chop finely, dice ham.
Preheat oven to 225 ° C.
Heat oil in a pan, sauté mushrooms briefly and remove it again. Add the chopped mushroom stems, onion and ham and roast all, season with garlic, herbs, salt and pepper and stir the mixture in the curd cheese. Cover a gratin dish with butter, put in the mushrooms and fill them with the quark mixture. Mix well sour cream with the egg yolk and spread with them the mixture. Sprinkle with cheese and put pats of butter on the mushrooms. Bake in the oven for about 30 minutes on until golden brown.