Filet mignon (French for "cute fillet" or "dainty fillet") is a steak cut of beef taken from the smaller end of the tenderloin, or psoas major of the beef carcass, usually a steer or heifer. In French this cut can also be called filet de bœuf, which translates in English to beef fillet. When found on a menu in France, filet mignon generally refers to pork rather than beef.
The tenderloin (not to be confused with the short loin) runs along both sides of the spine, and is usually harvested as two long snake-shaped cuts of beef. The tenderloin is sometimes sold whole. When sliced along the short dimension, creating roughly round cuts, and tube cuts, the cuts (fillets) from the small forward end are considered to be filet mignon. Those from the center are tournedos; however, some butchers in the United States label all types of tenderloin steaks "filet mignon." In fact, the shape of the true filet mignon may be a hindrance when cooking, so most restaurants sell steaks from the wider end of the tenderloin - it is both cheaper and much more presentable.
The tenderloin is the most tender cut of beef and is also arguably the most desirable and therefore the most expensive. The average steer or heifer provides no more than 500 grams of it. Because the muscle is notweight-bearing, it contains less connective tissue, which makes it tender.
Filet mignon is considered the king of steaks because of its tender, melt in the mouth texture. A prime filet mignon can literally be cut with a fork. This beef cut can be quite expensive when dining out, but much more reasonable to make at home, especially if you purchase a whole tenderloin.
Filet mignon is French, of course, with filet meaning "thick slice" andmignon meaning "dainty." It first appears in American print in 1899. Filet mignon comes from the small end of the tenderloin (called the short loin) which is found on the back rib cage of the animal. This area of the animal is not weight-bearing, thus the connective tissue is not toughened by exercise resulting in extremely tender meat.
The tenderloin term (also erroneously called chateaubriand) applies to the entire strip of tenderloin meat, whereas slices of the tenderloin are termed filet mignon. Filet mignon slices found in the market are generally 1 to 2 inches thick and 2 to 3 inches in diameter, but true mignons are no more than 1 inch in diameter and are taken from the tail end. Although this cut is very tender, the beef flavor is proportionately lessened. As such, it is often served with an accompanying sauce incorporating the pan juices.