Flank Steak is best suited for a London broil style of cooking. First you should score the meat lightly with a sharp knife to allow some of the marinade to get into the meat, then marinade form 2-8 hours. Broil or grill the meat to the proper internal temperature (see below), let it rest for 10 minutes and slice thinly across the grain. Always cut against the grain at a 45 degree angle to create thin strips of meat. This is very important for the texture and tenderness of the final product.
This cut should be cooked using an internal meat thermometer that is oven safe, no matter the method of cooking. These devices cost $20 and are critical for the best eating experience and are as useful a tool as a spatula. The internal Fahrenheit temperature goals are: 115-120 Extra-Rare (Bleu); 120-125 Rare; 125-130 Medium Rare; 130-135 Medium. Not recommended to go above 135 degrees.
Flank steak is a boneless, fibrous cut of meat from the abdominal muscles of the buffalo. The cut of meat is common in Colombia, where it is known as “sorbrebarriga” literally meaning “over the belly”. It is best sliced across the grain to maximize tenderness.