Preparation Preheat oven to 325°F. Place ham in roasting pan and bake until thermometer inserted into thickest part of ham registers 150°F., about 15 minutes per pound. Cool ham completely. (Can be prepared 3 days ahead. Cover and chill.) Bring cider and apples to boil in heavy medium saucepan over medium-high heat. Boil until liquid is reduced to scant 1 1/2 cups, about 8 minutes. Whisk sugar, vinegar and mustard in small bowl until blended. Add to cider mixture. Simmer sauce until reduced to 2 1/4 cups, stirring occasionally, about 6 minutes. (Can be made 1 day ahead. Cover and chill.) Preheat oven to 375°F. Cut eight 1/2-inch-thick ham slices from bone. Overlap ham slices in glass baking dish. Spoon sauce over. Bake until ham is heated through and sauce bubbles, about 25 minutes. Transfer to platter and serve.
Preparation Preheat oven to 325°F. Place ham in roasting pan and bake until thermometer inserted into thickest part of ham registers 150°F., about 15 minutes per pound. Cool ham completely. (Can be prepared 3 days ahead. Cover and chill.) Bring cider and apples to boil in heavy medium saucepan over medium-high heat. Boil until liquid is reduced to scant 1 1/2 cups, about 8 minutes. Whisk sugar, vinegar and mustard in small bowl until blended. Add to cider mixture. Simmer sauce until reduced to 2 1/4 cups, stirring occasionally, about 6 minutes. (Can be made 1 day ahead. Cover and chill.) Preheat oven to 375°F. Cut eight 1/2-inch-thick ham slices from bone. Overlap ham slices in glass baking dish. Spoon sauce over. Bake until ham is heated through and sauce bubbles, about 25 minutes. Transfer to platter and serve.