Combine dijon mustard and pineapple or orange juice. Brush over ham.
Remove plastic disc on bone (if your ham has one) and discard. Place the ham flat side down in a roasting pan. Cover tightly with foil. Roast 12-15 minutes per pound.
Meanwhile, combine glaze ingredients and bring to a boil. Simmer for 2-3 minutes, then leave to cool.
15 minutes before the ham is fully cooked, remove from the oven and turn oven up to 425 F.
Brush ham with glaze and place back in oven until caramelized and the ham has cooked to a safe temperature for eating.