Patty melt

A patty melt is an American grilled sandwich consisting of a ground beef patty topped with melted cheese and caramelized onions between two slices of griddled seeded-rye bread.

Description and ingredients
The patty melt is variously described as a variant of the traditional American cheeseburger, topped with fried onions and served on sliced bread instead of a traditional bun, or as a variant of a grilled cheese that includes a hamburger patty and fried onions.

The sandwich consists of a ground beef patty topped with melted cheese (traditionally Swiss cheese) and usually with caramelized onions between two slices of griddled bread (typically caraway-seeded rye or marbled rye, though sourdough or Texas toast are sometimes substituted in some regions, including the Southern U.S.) It is typically made without condiments or garnishes.

Like a grilled cheese, the patty melt maintains its structural integrity when eaten, as all ingredients are grilled at the same time and assembled while still hot, which melds the grilled bread, hamburger patty, cheese, and onions into a single unit that doesn't fall apart while being eaten.

History and origins
Sandwiches calling for hamburger patties to be placed into two slices of bread, rather that into a bun, date to the mid-1800s and were referred to as hamburger sandwiches. It is unclear when the patty melt was invented, but it was most likely the mid-20th century, either during the Great Depression or the postwar economic boom. Several culinary writers have suggested that Los Angeles restaurateur Tiny Naylor may have invented the patty melt sometime between 1930 and 1959, depending on the source;  it was on the menu at Tiny Naylor's in the early 1950s. Even if Naylor did not invent the sandwich, it is agreed that he and his family helped popularize the sandwich in their restaurants and in restaurants where they worked, which included Tiny Naylor's, Du-par's, and Wolfgang Puck's Granita.

Home cooking
Home cooks typically make patty melts in a cast-iron skillet in steps by separately grilling the patties, caramelizing the onions, assembling the sandwich, and then grilling it as for a grilled cheese sandwich. Gentleman's Quarterly called it "the great indoor burger".

Popularity
According to New York Times food writer Pete Wells in 2024, the sandwich is "virtually unknown" outside of the United States; Wells theorizes that the amount of space on a flattop grill required to grill onions, patty, and bread at the same time has restricted its appeal outside of typical short-order restaurants. It is typically on the menu of diners, coffee shops, and lunch counters, but in the early 2020s it started to appear on some upscale menus.