Have your butcher cradle your prime rib. If the roast doesn't have at least a sheath of fat on the top side (about 1/4 - 1/3 inch fat), ask for a sheet of rendering" tenderized. 24 hours before cooking, rub entire roast with seasoning. Wrap roast in rendering (if necessary). Tie with string. Apply seasoning to outside of rendering. Place in refrigerator for 24 hours.
When ready to cook, bring roast out of refrigerator 1 hour before it goes into the oven. Preheat the oven to 500 degrees.
Cook roast at 500 degrees for 30 minutes. Reduce heat to 350 degrees for 1 1/2 hours or until the internal temperature reaches 130 degrees.
(Do not open the oven door while the meat is cooking at 500 degrees or the house will fill up with smoke and you will lose the heat you need to sustain the perfect cookingtime for the roast!)
Serve with prepared horseradish, blended with sour cream if ou would like to lighten it.
Remove roast from oven and let rest covered with a towel for 30 minutes while the Yorkshire pudding bakes. Leave oven at 350 degrees.