Big Mac sauce
The Big Mac is a hamburger sold by the international fast food restaurant chain McDonald's. It was introduced in the Greater Pittsburgh area in 1967 and across the United States in 1968. It is one of the company's flagship products and signature dishes. The Big Mac contains two beef patties, cheese, shredded lettuce, pickles, minced onions, and a Thousand Island-type dressing advertised as "special sauce", on a three-slice sesame-seed bun. The Big Mac was created by Jim Delligatti, who stated later he did not invent the Big Mac but merely copied the double deck hamburger marketed by the Big Boy hamburger chain since the 1940s. Mr. Delligatti operated several McDonald's restaurants in the Pittsburgh area. It was created in the kitchen of Delligatti's first McDonald's franchise, located on McKnight Road in suburban Ross Township.
Source: Wikipedia