There is a great debate on how well cooked your burgers should be. When I enjoy steak, there's no question to how done I like it: medium rare, baby! But with steaks, any harmful bacteria sits on the surface of cuts of meat. They are killed off by searing and cooking the meat, even when the center is left rare. But burger meat is minced and mixed together, so the harmful bacteria is all over, including the center of the meat and can only be killed if cooked completely. This is the case whether you are using ground beef or ground lamb. Cooking your lamb burger to medium heat internally doesn't mean you are left with a dry burger. However you like to enjoy your burger, I give instructions for either doneness in the recipe below.