Wash and blanch the heels. Put in a saucepan and cover with cold water or stock and simmer very gently for about 3 hr. Melt the fat in a saucepan, add the flour and cook without colouring. Add 1 pt. of the stock in which the cow heels were cooked, stir well until boiling, simmer for 5 min., add parsley and seasoning to taste. Remove the bones from the meat and arrange the pieces of meat on a hot dish. Pour the sauce over and serve hot.