Prepare the meat and cut into 2-in. squares. Slice the onion, melt the fat, add the onion, bay leaves, cloves, mace, peppercorns, salt, pepper and meat. Cover and cook very gently for about ½ hr., stirring frequently. Add boiling stock or water and simmer for about 1½ hr. or until tender. Mix the flour smoothly with a small quantity of cold water. Gradually add to it, stirring all the time, about ½ pt. of the liquor from the saucepan. To this sauce add the meat, bring to the boil and simmer until tender. Serve on a hot dish within a border of mashed potatoes, sprinkle the capers over the meat.