A pre-cooked, spiral-sliced ham provides you with an entree that's both simple to prepare and convenient to serve. Such hams are particularly popular for holiday meals and buffet dinners. As its name implies, pre-cooked ham has been previously baked, smoked or cured and comes ready to eat. By placing the ham in the oven, you're simply warming the meat to bring out its flavor and aroma. Before you put the ham in the oven, you can also apply a flavorful glaze to lightly caramelize the meat’s surface. Spiral-sliced hams are sold already cut to the bone into thin, continuous slices, so the meat is easy to serve.
PREHEAT THE OVEN: Place your oven rack on the lowest level. This allows the center of the ham to remain in the center of the oven while baking, ensuring that it's cooked evenly and thoroughly. Check the ham’s packaging for heating recommendations and heat the oven accordingly; otherwise, heat it to 325 degrees Fahrenheit. According to the USDA, you shouldn't cook meat at temperatures any lower than this.
PREP THE HAM: Remove the wrapping and any additional covering on the ham. Select a large broiling pan or roasting pan. If using a lightweight, disposable aluminum pan, place it on a baking sheet for stability. Aluminum pans on their own are often too flimsy to control and may cause you to drop them or spill hot broth.
GET READY FOR BAKING: Place the ham cut-side down in the pan. Cover the roasting pan with a lid or cover the ham tightly with aluminum foil to keep it from drying out.
COOK THE HAM: Heat the ham for about 10 to 18 minutes per pound at 325 degrees Fahrenheit. Allow approximately two hours for a half ham and three hours for a whole ham.
GLAZE THE HAM: If you'd like, use a pastry or basting brush to glaze the ham as desired. If your glaze contains sugar, wait until the last hour of cooking to apply it so it doesn’t burn. If you are using a ready-to-use glaze that came with the ham, follow the directions on the packet.
CHECK THE TEMPERATURE: Periodically check the ham’s temperature with an instant-read thermometer, taking care to place the thermometer so it touches the meat only and not the bone. Replace the lid or foil after checking the temperature. To prevent the ham from drying out, limit the amount of times you open the oven.
FINISH COOKING: Remove the ham from the oven when it reaches an internal temperature of at least 145 degrees Fahrenheit if the ham was packaged in a USDA-inspected plant (at least 165 degrees Fahrenheit if it wasn't), according to the USDA. Again, make sure the tip of the thermometer does not come in contact with the bone when taking the temperature.
LET SIT BEFORE SERVING: Allow the ham to rest for 20 to 30 minutes after removing it from the oven and before serving it. This will make it easier to pull apart the already-cut pieces.