Preheat the oven to 180 ° C (Th.6).
Brown the meat on all sides in the oil and butter and place in the center of a large baking dish. Arrange onions and potatoes all around (if new, you can keep the skin ), salt, pepper and put 1 hour 15 minutes in the oven. Using a blender, reduce the hazelnuts to a powder. Mix the hazelnut powder and the cream. 25 cl thick cream Pour the cream of hazelnuts on the meat 5 min. before the end of cooking.
Let the square rest a few minutes under a sheet of aluminum foil before cutting it following the bones.
Serve veal chops covered with hazelnut cream and served with potatoes and onions.