(3 days before cooking) Make the marinade sauce. In a bowl, mix together all of the ingredients except for the prime rib. Stir really well. Then cover the bowl with a lid and refrigerate for 24 hours. Note: Throughout the day as you visit the fridge, swirl the ingredients around to keep them mixed or give them a quick stir and then place back in the fridge.

(2 days before cooking) Marinade the prime rib roast. Place the prime rib in a large pan with sides. (We like to use a glass casserole dish with sides. ) Rub the marinade all over the rib roast. Be sure to coat all sides of the roast. Cover the dish completely with cling wrap. Place the pan in the fridge and allow it to marinate for 2 days.

Day of cooking. Remove the rib roast from the fridge 2 hours before cooking and allow it to come to room temperature. 

Preheat the oven to 450 F degrees.

Remove the roast from the baking dish and remove the cling wrap.

Place the rib roast on a baking rack that's nested into a high-sided baking pan. 

Bake the rib roast at 450 F for 30 minutes to sear the outside of the meat. 

Reduce the oven to 250 F and cook for an additional 2 hours or until the roast reaches an internal temperature of 125 F for rare prime rib. 

Save the meat juice to make au jus.