Cooking the Prime Rib
When serving a bone-in prime rib, a rack of bones will remain after the majority of the meat has been consumed. Though many chefs throw these bones away, they can be cooked and used to create delightful meals the following day. The first step to having useful bones is roasting the prime rib correctly. After seasoning the prime rib with herbs, salt and pepper, set the roast in a wide, deep pan with the bone side down. The bones act as a natural rack for the roast, propping it up in the pan and catching a lot of the juices and fat that fall from the roast while cooking. Allow the roast to stand at room temperature for 2 to 4 hours, or until no longer cold. Slide the roast into an oven preheated to 450 degrees F, and allow the meat to sear for 15 to 20 minutes. Then drop the oven temperature to 325 degrees F. Roast the meat, basting with the fat from the bottom of the pan every 30 minutes, until the desired internal temperature is reached. The appropriate internal temperature for a cooked prime rib ranges from 120 degrees F for a rare roast to 160 degrees F for a well-done roast. Allow the meat to rest for about 30 minutes, then serve. Store the leftover bones in the refrigerator.
Roasting the Leftover Bones
Roasting the leftover bones provides delightful fodder for a meal the next day. Place the bones in a pan and rub them with some sort of fat (such as butter or oil) and herbs (such as garlic). The fat will crisp the meat on the bones, and the heat will infuse the bones with the herbs. Roast the bones at 400 degrees F for 20 to 30 minutes, or until the meat on them is crisp and the bones are golden brown. Serve them as-is, or remove the roasted meat from the bones and use it in a hash, a stir-fry or any other recipe that calls for bits of beef.
Making a Stock
Leftover rime rib bones, particularly those that don't contain enough leftover meat to make a meal on their own, can also be stewed and used for soup stock. Put the prime rib bones in a pot with some diced onions, celery, carrots, garlic and olive oil. Cover the bones and vegetables with water, and cover the pot with a lid. Simmer over medium-low heat for about 2 hours. Remove the bones from the stock and scrape off any meat that remains on them. Add the meat back into the stock, along with barley, potatoes, rice, or any other vegetables or starches that appeal to you. Simmer until the vegetables and starches are cooked.