Preheat oven to 325F.
Score fat in a crosshatch pattern, place ham on a rack set over a roasting pan with 1 cup water or stock. Loosely cover with foil and roast 1 hour.
Meanwhile make glaze by combining marmalade, sherry or balsamic, and lots of pepper. Stir in rosemary and cook until thickened slightly.
After the hams been cooking for an hour, baste it with half of the glaze, then roast another 30 minutes uncovered. Baste with remaining glaze and roast 15 minutes more. Remove ham from oven and let stand under parchment and foil for up to 30 minutes. Carve and serve with Broiled Pineapple, Mashed Potatoes and Leeks, and Warm Biscuits with Honey Butter alongside.