INSTRUCTIONS
1. Adjust oven rack to middle position and heat oven to 325 degrees. Using clean, stiff-bristled brush, scrub ham under cold running water to remove any surface mold. Transfer ham to cutting board and trim off dry meat, skin, and all but ¼ inch of fat. Score fat cap in 1/2-inch crosshatch pattern, ¼ inch deep.
2. Transfer ham to roasting pan fat side up, add 1 quart water, and cover pan tightly with aluminum foil. Bake until thickest part of meat registers 140 degrees, 4 to 5 hours. Remove ham from oven, discard foil, and increase oven temperature to 450 degrees.
3. Combine sugar, mustard, and pepper in bowl and rub over top of ham. Return ham to oven and cook, uncovered, until glazed, 12 to 17 minutes. Transfer ham to carving board and let rest for 20 minutes. Carve thin slices and serve.
