This is a term which has several meanings. It is often used to describe the preparation of raw beef called steak tartare. Raw beef is chopped finely and served with minced onion, parsley, capers, and seasoned with anything from Worcestershire sauce to Tabasco sauce. Tartare sauce describes a mayonnaise based sauce with capers, onion, hard cooked eggs, cornichons, and herbs.
tar-TAR. Traditionally a dish of coarsely ground or finely chopped high-quality, raw lean beef that has been seasoned with salt, pepper and herbs. It's thought to have originated in the Baltic provinces of Russia where, in medieval times, the Tartars shredded red meat with a knife and ate it raw. Also used as a generic term for any finely chopped, seasoned meat or fish such as salmon or tuna tartare.