salt and pepper about 1/4 pint beef stock Soak the stomach bag in salted water overnight. Place the pluck (lights, liver and heart) in a saucepan with the windpipe hanging over the edge. Cover with water and boil for 1 1/2 hours. Impurities will pass out through the windpipe and it is advisable to place a basin under it to catch any drips. Drain well and cool. Remove the windpipe and any gristle or skin. Mince the liver and heart with the mutton. (Add some of the lights before mincing if you wish.) Toast the oatmeal gently until pale golden brown and crisp. Combine with minced mixture, suet and onion. Season well and add sufficient stock to moisten well. Pack into the stomach bag, filling it just over half-full as the stuffing will swell during cooking. Sew up the bag tightly or secure each end with string. Put an upturned plate in the base of a saucepan of boiling water, stand the haggis on this and bring back to the boil. Prick the haggis all over with a large needle to avoid bursting and boil steadily for 3 to 4 hours. Makes 6 to 8 servings.