Heat the oven to 275°F. Put the ham in a roasting pan or a big cast-iron skillet. Cover it loosely with foil and heat it for 7-1/2 to 8 hours. Let the ham rest for at least 20 minutes. Before carving, remove the fat and rind from the surface of the ham, if you like. Serve with biscuits and mustard or your favorite chutney.