how long do you cook a ham roast
1 Pour enough water into the bottom of the roasting pan to come to a 1 inch depth. Cover the pan tightly with aluminum foil or a lid.  Bake for 4 1/2 to 5 hours in the preheated oven (about 22 minutes per pound), or until the internal temperature of the ham has reached 160 degrees F (72 degrees C).