Loose meat sandwich

A tavern sandwich is a sandwich consisting of ground beef on a bun, sometimes mixed with sauteed onions, and sometimes topped with pickles, ketchup, mustard, raw onions, and/or cheese. Unlike a hamburger, a tavern's meat is cooked loose rather than formed into a compact patty. It more closely resembles a sloppy joe, without the tomato-based sauce. Carroll Dietz of Missoula, Montana, created the precursor to the tavern sandwich in 1920, referred to as a "steamed hamburger." In 1926, Fred Angell began selling his version of the sandwich at the first Maid-Rite restaurant in Muscatine, Iowa, under the name "loose meat sandwich." The name "tavern" for the sandwich is credited to David Heglin. Heglin sold the sandwiches at his Sioux City, Iowa, restaurant in 1924. After Heglin died, Abe Kaled bought the business in 1934 and renamed the restaurant Ye Olde Tavern after the sandwich. Kaled perfected the recipe for the ground beef, and the tavern sandwich spread to restaurants and bars across the Sioux City area.

Source: Wikipedia