You'll need 2 1/2 pounds of bone-in ribeye steak for this recipe at about 1 inch thick each. I would suggest going with USDA Prime or Choice grade ribeye steaks. If you use a larger cut, keep an eye on the temperature for doneness. You can use this method with boneless ribeye as well, but again, keep an eye on the temperature as boneless cuts cook quicker than bone-in.
Regular unsalted butter or flavored buttered work well here.