Italian beef is a popular Chicagoan sandwich consisting of thinly sliced, seasoned layers of roast beef in a dense and chewy Italian-style roll, topped with either pickled giardiniera relish or roasted green bell peppers. The sandwich is typically dipped in jus - on one end, both ends, or completely soaked in the flavorful gravy.
Additionally, mozzarella or cheddar cheese can be added to the sandwich, according to personal preferences. There are three popular theories about the origin of the Italian beef sandwich. One says that is was invented by Al Ferreri (the owner of Al's Beef restaurant) and his family at the start of World War II.
They invented it in response to big Italian weddings that needed to stretch a small amount of food a long way. Another theory says that the sandwich is a version of the French dip, introduced in Los Angeles in 1918. According to Pat Bruno, a critic for the Chicago Sun-Times, it was invented by a man named Tony who worked in a Greek diner and messed around with the French dip recipe, creating the Italian beef sandwich in the process.