Bone-in or boneless prime rib both work beautifully here, though bone-in offers the most flavor. If buying bone-in, ask your butcher to cut the bones off and tie them back onto the roast — this creates a natural roasting rack and makes carving easier later. If using a boneless roast, place it on a rack inside your pan. I’ve had great success using the wire rack from my Instant Pot set inside a cast iron skillet.