Prepare a béchamel sauce with butter, flour and milk. When it has cooled down, stir in the egg yolks, salt and add the egg whites. Bake 4 pancakes in a frying pan. Three of them are covered with chopped mushrooms, the fourth one is put on top. The whole thing is baked again in the oven.
Tip: Use your favorite ham – then your dish tastes twice as good!