A Reuben is a sandwich traditionally consisting of corned beef, sauerkraut, Swiss cheese, and Russian dressing served on Rye bread and grilled. Contrary to popular belief, the Reuben was invented right here in the United States, although the exact origin within the US is unclear there are a couple of different theories that you can read about on Wikipedia. Nowadays there are many variations of this well-loved sandwich. You can find it with ham, pastrami, or turkey instead of corned beef and it is most commonly served with Thousand Island dressing rather than Russian dressing.