Add potatoes, onion, garlic, and pepper to a large pan, and saute for about 4-5 minutes. Warm the leftover prime rib in the microwave with a little au jus to remoisten. Next, either poach or fry an egg. To serve, invert hash onto serving platter. Top with egg.
Use left over prime rib and save the juice. Dice the prime rib, chop potatoes (baked, cold ones work great), onion and green pepper. Saute the ingredients in a little bit of olive oil until onion and peppers are tender, add beef juice. Salt and pepper to taste.