In English butchery, flank refers to the section of meat located on the animal's lower abdomen, beneath the loin, and adjacent to the belly.
Distinct from the thick flank located on the animal's rear part, the flank is a long, flat cut with a rich, beefy flavor due to its well-exercised muscle fibers. Flank is lean, fibrous, and grained, with pronounced muscle structure. Its inherent leanness means it lacks the marbling found in some other cuts, but it compensates with a deep, meaty flavor.
It's popularly used for dishes like London broil where it's marinated, quickly grilled or broiled, and then thinly sliced against the grain to ensure tenderness. Additionally, it's a common cut used for traditional British steak and kidney pies.
It's crucial to slice flank steak against its pronounced grain to break down the long muscle fibers and ensure each bite is tender. Overcooking can lead to a tough texture, so many chefs recommend cooking it to medium-rare or medium doneness at most.