beef Flank
Flank Steak
Flank is the abdominal wall — one flat sheet of muscle per side, carrying the coarsest and most visible grain on the animal. Everything about cooking it follows from that: hot and fast to medium-rare, rest, then slice thin and hard across the grain. The knife does more for tenderness here than any marinade will.
Buy it if
You want a lean steak that feeds four or five, and you're willing to slice it properly.
Where it comes from: the rectus abdominis, the sheet of muscle running along the belly. It works constantly to hold the animal's abdomen up, which leaves it lean, dense and strongly flavored, with long parallel fiber bundles you can see from across the room.
Why slicing matters more than anything else: those fibers run the length of the steak. Chewing through a long fiber is work; chewing one that is already a quarter-inch long is not. Slicing thin and across the grain shortens every fiber before it reaches your mouth. Slice the same steak the other way, cooked identically, and it eats like rope. This is the largest single variable on the plate.
What a marinade actually does: it seasons the outer few millimeters. Salt and acid move through meat slowly — an overnight marinade does not reach the middle of an inch-thick steak, and it does not dissolve what makes flank chewy. Marinate it because you want the flavor. Don't marinate it expecting the tenderness that only the knife delivers.
How to cook it: hot and fast to medium-rare, and stop there. It is lean enough that past medium the fibers tighten and there is no fat to cover for it. Rest it before slicing, then cut thin, across the grain, at a slight angle.
Where it comes from on the animal
| Species | beef |
|---|---|
| Primal | Flank |
| Subprimal | flank (rectus abdominis) |
What else it’s called
How to cook Flank Steak
| Best methods | Grill Broil Pan sear Sous vide |
|---|---|
| Cook to | Hot and fast to medium-rare. Rest, then slice thin across the grain — that matters more than the temperature does. |
Flank Steak vs Skirt Steak
Both thin belly/flank steaks; skirt is fattier and more intensely beefy, flank is leaner.
| Flank Steak | Skirt Steak | |
|---|---|---|
| Primal | Flank | Plate |
| Thickness | About an inch | About half an inch |
| Fat | Lean | Moderate |
| Marbling | Light | Moderate |
| Under the label | One muscle per side | Two steaks — outside skirt is thicker and better marbled than inside |
| Best method | Grill | Grill or Pan-sear |
Full Flank Steak vs Skirt Steak comparison →
If Flank Steak is sold out
Cooks like
Skirt Steak
Both are thin, fibrous steaks — marinate, sear hot, slice thin across the grain.
Common questions
Is London broil the same thing?
London broil is a method, not a cut — broil it, then slice thin across the grain. It was originally done with flank, but in most American supermarkets the London broil label now sits on top round, a different and less forgiving muscle. Check what is under the label before you plan the cook.
Which way does the grain run?
Lengthwise, from one short end to the other, and it is unusually easy to see — look for the parallel lines on the surface and cut at right angles to them. If you're unsure, make one cut and look at the face: you want to be seeing the ends of the fibers, not their length.
Is flank the right cut for fajitas?
It is the usual substitute rather than the original. Fajita comes from faja, Spanish for belt or sash, describing the long strip shape of a skirt steak. Flank stands in well because it wants the same treatment: marinate, sear hard, slice thin across the grain.