Cibola Farms sells both pre-formed sirloin patties and ground sirloin. The choice between the two options for cooking burgers is purely personal.
Pre-formed patties are extremely popular and are very convenient. You can simply pop as many of them out of the package using a knife to very carefully separate them while frozen, then put the remainder into a ziplock bag and back into the freezer. You can also cook them frozen. Just flip them often, and every time you see red juices beading up at the top. The internal doneness can be measured by the color of this juice. Please keep in mind that buffalo meat is redder than beef and medium is a light red color; medium well is a pink color; well done is brown throughout.
Hand-crafted sirloin burger patties are the favorite with the farm crew. These are formed using bulk ground sirloin. Because you can make this any thickness that you like, and because you can mix in any ingredients to the meat that you like, they tend to be more juicy and more flavorful. Unlike the preformed patties, you do not cook based upon the color of juices surfacing at the top, but best to cook using your finger to test the imprinting of the center of the patty as you are cooking it. Plan to flip at least four times.