From Wikipedia, the free encyclopedia. A patty melt is a type of hamburger consisting of a hamburger patty and Cheddar or Swiss cheese between two slices of bread (traditionally rye, though sourdough is sometimes substituted). Patty melts are sometimes prepared using marbled rye bread. In some places, especially in the U.S., a patty melt can consist of only the patty of a hamburger, with cheese, on a single piece of toast/bun. The hamburger is then fried with butter on a frying pan so that the cheese melts thoroughly.