1 shank-end smoked ham, about 5 lbs.
1 Tb. butter
2 Tbs. peeled and minced fresh ginger
3 Tbs. dark rum, bourbon or fresh orange juice
1/2 cup bitter orange marmalade
1 Tbs. Dijon mustard
Position a rack in the lower third of an oven and preheat to 325°F. Line a roasting pan with aluminum foil and place a roasting rack in the pan.
Using a sharp knife, score the fat on the ham in a crosshatch pattern, creating 1 1/2-inch diamond shapes. Place the ham, flat side down, on the rack in the roasting pan. Add 2 cups water to the pan and cover loosely with aluminum foil. Bake until an instant-read thermometer inserted in the thickest part of the ham away from bone registers 125°F, about 1 1/4 hours.
Meanwhile, make the glaze. In a small saucepan, melt the butter over medium heat. Add the ginger and cook, stirring occasionally, until it softens, about 2 minutes. Add the rum and boil until it is reduced by half, about 2 minutes. Stir in the marmalade and mustard and bring to a boil, then remove from the heat and set aside to cool.
Remove the ham from the oven and discard the foil on top. Increase the oven temperature to 400°F. Spread the glaze all over the ham, forcing some of it into the scoring marks. Return to the oven and bake, uncovered, until the glaze melts onto the ham, about 15 minutes.
Transfer the glazed ham to a carving board. Let stand for 15 minutes, then carve into slices parallel to the bone. Serve hot or warm. Serves 12.