Cover the Prime Rib Roast Roast liberally with salt, pepper, onion and garlic and sear in a hot pan with the oil over high heat. Transfer the pan to a 250 degree oven and continue cooking for about two and a half to three hours, about 30 minutes per pound, or until an internal read thermometer reads 130 degrees. Towards the end of the roasting time, combine milk, flour, eggs and salt. Whip with a whisk or hand mixer to incorporate air and set aside. Remove pan from oven and place the Prime Rib Roast on a platter to rest for 20 minutes. Bring oven temperature up to 450 degrees. Drain off liquid from roasting pan and reserve. Return pan to high heat and add wine, using a wooden spoon to scrape all of the drippings up. Reduce wine by half and add beef stock and reduce by half. Separate the fat and the liquid from reserved drippings. Add liquid to the Au Jus and whisk in the mustard and Worcestershire and set aside. In a muffin tin, add equal portions of the reserved fat into the bottom of each muffin tin. Add the flour mixture to each tin and fill half way. Place into a 450 degree oven and bake for 15 minutes. Be careful not to open the oven while the pudding is baking or it could fall. Remove and serve.