The grain of the meat is the direction that the sting-like fibers of the muscle run. With a certain cut of meat, like this flank steak, it is very important to cut the meat against the grain. If you cut the meat parallel to the grain the meat, even if it is cooked properly, it will be stringy and fibrous. To get the most from this steak, a brisket, London broils, and other tougher cuts, always cut them against the grain.
To get nice broad slices, hold a fork at about a 45-degree angle. Use a thin slicing knife and follow the angle of the fork as you cut against the grain. The deeper the angle the wider the cuts. Continue down the steak until it is cut into even slices. It is best if the slices are very thin.

Instructor: Robert Bleifer.