The e-mail discussion list for the American Dialect Society offers this description for a food apparently known as a “Juicy Lucy”:
Juicy Lucy—This is a cheeseburger, but with the cheese inside the burger. It appears to be the product of Matt's Bar, 3500 Cedar Avenue, Minneapolis, MN, but several other places in that town also offer it. Not recorded in Mariani’s Encyclopedia of American Food & Drink or in DARE.
To be honest, the idea of having cheese inside my burger initially sounded a bit gross to me. But, perhaps I was just thinking in an American-cheese state of mind. And, come to think of it, I would imagine that a “Juicy Lucy” made with blue cheese could be quite delicious!