Salt and pepper the roast generously all over and place it on a rack on a cookie sheet in the fridge not covered for overnight or as much as 48 to 72 hours.
Remove from frig and brush the roast with clarified butter or olive oil. *Optional, rub on any dried herbs you may want to use such as thyme, rosemary or Herbs de Provence.
If you do not have a rack or a cookie sheet, add celery, carrot onion in the bottom of a roasting pan and bake the prime rib that way.
Insert meat thermometer half thru roast.
Cook approximately 3+ hours for a Rare to Medium Rare cook. Internal thermometer should read 120 degrees F.
Remove roast from oven and tent loosely with aluminum foil. Place in a warm spot in the kitchen and allow to rest for at least 45 minutes and up to 90 minutes.
Preheat oven to highest possible temperature setting, 500 to 550°F. Rub the roast with butter, mostly on top.
Place back in the oven for 10 minutes.
Remove, slice and serve.