Flank steak

Flank steak is a cut of beef steak taken from the abdominal muscles of the cow, located just behind the plate and in front of the rear quarter. It is a long, flat cut with a significant grain, and is known for its bold flavor and chewiness.

Terminology
In Brazil, it is called bife do vazio or pacú (many people confuse with fraldinha, which is actually the flap steak). It is popular in south Brazil, specifically in Rio Grande do Sul state. The cut is also common in Colombia, where they call it sobrebarriga ("over the belly"); sobrebarriga a la brasa is a Colombian recipe for braised flank steak. Argentina, Uruguay call flank steak churrasquito de vacío or bife de vacío. In Spain and Cuba, it is known as filete de falda.

Use
Flank steak is used in dishes including London broil and as an alternative to the traditional skirt steak in fajitas. It can be grilled, pan-fried, broiled, or braised for increased tenderness. Grain (meat fibre) is noticeable in flank steaks, as it comes from a well-exercised part of the cow, and many chefs cut across the grain to make the meat more tender. It is often used in Asian cuisine, is sold in Chinese markets as "stir-fry beef", and is served in French cuisine as an at-most medium-rare steak. Flank also serves as a common cut for steak jerky.