Italian beef

An Italian beef is a sandwich, originating in Chicago, made from thin slices of roast beef simmered and served au jus on French bread. Common toppings are a choice between spicy giardiniera or mild bell peppers (called "sweet"). The entire sandwich is traditionally dipped in the juice the meat is cooked in before serving with a side of French fries. The sandwich traces back to Italian American immigrants in Chicago as early as the 1930s, but the exact origin is unknown. The sandwich gradually grew in popularity and was widely eaten in the city by the 1970s and 1980s. The sandwich saw a substantial rise in popularity upon the release of the television show The Bear, set in a fictional Chicago restaurant which specializes in the sandwich.

Source: Wikipedia