A crown roast is made up of 2 to 3 racks of bone-on pork loin that a butcher ties together end to end to create a large round roast. Make sure to order the roast from your local butcher a couple of days in advance so they have time to get the right size racks, clean the meat from the tips of the bones (called Frenching) and tie them together securely so it cooks evenly.