Beef flank steak

The flank steak, also known as bavette, is a beef steak cut from the abdominal muscles of the cow. A relatively long and flat cut of meat, flank steak is used in a variety of dishes including London broil and fajitas. It is significantly tougher than the other beef cuts; therefore, many recipes use moist cooking methods such as braising.

Mexico's version of the flank steak has gained fame throughout Latin America. It originates in the city of Monterrey and is known as arrachera[dubious – discuss] in Mexican cuisine. It may be tenderized by using commercial tenderizers, or by mechanical tenderizing, using a method to create an even cut. A different version of the arrachera is known as entraña, the difference being that the latter retains a thick layer of the fat surrounding the muscle, making it a juicier and saltier steak. The French are quite partial to this cut, known as bavette. It is quickly seared in a hot pan and eaten rare to maintain its tenderness. Bavette is frequently served in Parisian bistros with shallots - "Bavette a l'échalotte". The cut is also popular in Colombia, where it is known as sobrebarriga, literally meaning "over the belly".

Flank steak is best when it has a bright red color. Because it comes from a strong, well-exercised part of the cow, it is best prepared when cut across the grain.

Flank steak is frequently used in Asian cuisine, and in Chinese markets it is often sold as "stir-fry beef" because that is how it is usually prepared. Most stir-fried beef dishes in Cantonese restaurants are prepared with this cut of beef.

McDonald's in the United Kingdom uses "100% forequarter and flank" in its burger patties.
Source: http://en.wikipedia.org/wiki/Flank_steak