Wipe a slice of veal one-half inch thick, weighing one and one-half pounds, and cook in frying-pan without butter, quickly searing one side, then the other. Place on a board and cut in one and one-half inch pieces. Fry two sliced onions in one-half cup butter until brown, remove onions, and add to the butter, meat, and one-half tablespoon curry powder, then cover with boiling water. Cook slowly until meat is tender. Thicken with flour diluted with enough cold water to pour easily; then add one teaspoon vinegar. Serve with a border of steamed rice.