Cooking prime rib in a slow cooker involves layering the ingredients and allowing the meat to cook undisturbed for several hours. Prime rib is typically cooked in the slow cooker with vegetables.
To cook prime rib in a slow cooker, pour 1 cup red wine and 1 cup beef stock into the well. Add 1 bay leaf, and stir to combine. Next, layer in the chosen vegetables, such as chopped celery, red onion, carrots and scrubbed fingerling potatoes. Season with smashed garlic and 1 teaspoon each dried rosemary, sage, salt, ground black pepper and garlic powder.
Some recipes call for browning the meat before placing it in the slow cooker. In this case, heat 1 tablespoon oil in a skillet, and add the roast. Brown the roast on all sides. For this recipe, mix the dried herbs with 1 teaspoon liquid smoke and 1 teaspoon Worcestershire sauce, and rub over the surface of the roast.
Place the meat with the fat side up on top of the vegetables in the slow cooker. Cover with the lid, and turn the cooker to low heat. For rare prime rib, cook until the meat's internal temperature reads 135 degrees Fahrenheit, which takes roughly five hours. For medium doneness, cook until the internal temperature reads 145 degrees F or roughly six hours.