Salt and pepper the schnitzel. Heat the clarified butter and fry the schnitzel well on both sides. Then place the schnitzel in a baking dish. Cut the onions into rings and the ham into cubes. Fry them together until golden and season with salt and pepper. Spread the onion and ham mixture on the schnitzel in the tin. Mix the cream and wine together and pour over the schnitzel.
Let it steep overnight, then bake the next day in a preheated oven at 125 degrees for about 60 to 70 minutes.