Crank your leftovers from our Prime Rib Roast and Horseradish Cream recipe up to 11 with this truly excellent sandwich that you can make right in your June. No leftovers? Use deli roast beef and prepared horseradish instead. The key here is not to overcook the tender beef, so this is where the cheddar plays two roles--it adds another layer of delicious flavor and acts as a protective buffer for the meat at the same time.