Preheat your oven to about 250 to 300 degrees Fahrenheit – depending on the quality of your oven. Give it some time to warm up thoroughly.

Place your leftover prime rib in a roasting pan and pour several tablespoons of leftover au us or beef broth on top of it.

Cover the pan tightly with some aluminum foil and put it in the oven. This will ensure that the meat remains juicy.  

Let the meat reheat in the oven until it reaches an internal temperature of 160 to 165 degrees Fahrenheit. It will take around 10 minutes or more depending on how hot your oven is.

Remove the reheated prime rib from the oven and place the pan on your countertop. 

Heat up a skillet on high flame and put some butter in it. Let the meat sear a little so that it can become crispy on the outside.

Put the cooked prime rib in a platter and pour some au jus on it. That’s it, you can now serve the prime rib!