Some Wisconsinites may know cannibal sandwiches because they're a family tradition — or because of the warnings from the Centers for Disease Control and Prevention. Cannibal sandwiches are a Midwest staple. Consisting of fresh raw beef on rye bread topped with chopped onion, and a sprinkle of salt and pepper, the dish makes some squirm and others lick their chops. Last December, the popular dish even gained international attention with a tweet from the Wisconsin Department of Health Services that warned against eating raw meat. But where did the tradition come from? Why is it so popular in Wisconsin?