Bake the ham in roasting pan, uncovered, in a 350ºF. oven for 1 1/2 hours. Remove from oven and cut off skin. With a sharp knife, score fat into diamond shapes. Place a whole clove in the center of each diamond. Spread mustard over ham. Then press on brown sugar. Secure pineapple slices on ham with toothpicks. Bake an additional 30 minutes, basting frequently with pineapple juice. Serves 10 - 12