Flank steak is a versatile cut of beef that imparts quite a bit of flavour. This beef cut can turn stringy and tough when it isn't cooked properly, so take care to marinate the meat and choose appropriate cooking methods and recipes. If you can't find flank steak, though, a variety of other beef cuts make good substitutes.
While flank steak is generally a large cut of beef approximately 12.5 to 15 cm (5 to 6 inches) in width, skirt steak is usually longer and thinner. Skirt steak, a cut of beef that is boneless and comes from the brisket, is an appropriate substitute -- like flank steak, this is a tough piece of meat; however, with proper cooking it can become quite tender. Skirt steak is traditionally used to make fajitas, a Mexican speciality dish.
Hanger steak offers an acceptable alternative to flank steak. Cook this cut of meat carefully -- when overcooked, it becomes quite tough. The hanger steak is located at the last rib of a cow and attached to the diaphragm and kidney. This flavourful cut is not often found in your local supermarket meat counter, so you may need to go to a butcher's shop to buy the cut. It generally contains very little fat.
Also called the top round roast or the butterball steak, the top round cut of beef makes a good substitute for flank steak, particularly if you plan to make a London broil. It is the largest cow muscle and often used to make deli roast beef and large roast recipes. For best results, broil, braise or hob round in liquid.
The tri-tip cut of beef gets its name because of the triangular shape of the meat. This lean cut contains only small amounts of fat marbling and is a good option for replacing flank steak in recipes. Many people use the tri-tip roast for making chilli, and it is also often ground into hamburger meat.