how to cook a small prime rib roast in oven
1 While the roast is resting prepare the au jus; place the roasting pan on top of the stove over high heat. 2  Add in the wine; cook for 8-10 minutes, stirring and scraping any brown bits. 3  Add in the beef stock; cook and reduce the juice by half (this might take about 20 minutes). 4  Add salt and pepper to taste. Set oven to 450Â°F and allow the oven to preheat for a minimum of 15 minutes. 2  Season the roast with only a small amount of salt but lots of fresh ground black pepper pepper (that's all nothing else but a little salt and fresh ground black pepper, using any other spices will take away the flavor from the prime rib!).