More featured recipes » French Dip sandwich or Roast Beef Au Jus, traces its origin to a restaurant in downtown Los Angeles in 1918, when a local restaurant owner was making a sandwich for a police officer and accidentally dropped a French roll into a pan containing beef drippings. The Au Jus sandwich , also known as aor, traces its origin to a restaurant in downtown Los Angeles in 1918, when a local restaurant owner was making a sandwich for a police officer and accidentally dropped a French roll into a pan containing beef drippings. Image credit