Italian-Style Roast Beef is thin slices of seasoned roast beef with pan au jus made from the drippings. Most often it is served on a firm, long roll which can be dipped or doused in the au jus. In the early quarter of the century, Italian immigrants who worked for stockyards were known to take home the tougher cuts of meat and slow roast them with heavily seasoned broth to make the beef more tender. It was also apparently thinly-sliced to make it serve more people. It quickly became one of the most popular sandwiches and is still know as a Chicago classic.