Filet mignon

Filet mignon is a cut of meat taken from the smaller end of the tenderloin, or psoas major of a cow. In French, it mostly refers to cuts of pork tenderloin. The tenderloin runs along both sides of the spine, and is usually butchered as two long snake-shaped cuts of meat. The tenderloin is sometimes sold whole. Filet mignon is usually presented as a round cut taken from the thinner end of a piece of tenderloin. It is often the most tender and lean cut. Filet mignon often has a milder flavour than other cuts of meat and as such is often garnished with a sauce or wrapped with bacon. Due to the small amount of filet mignon able to be butchered from each animal it is generally considered one of the most expensive cuts of beef.

Source: Wikipedia