Cutting beef against the grain is a technique used to improve the tenderness and flavor of the meat. The grain refers to the direction of the muscle fibers in the beef. When you cut against the grain, you are slicing across the muscle fibers, which makes them shorter and less tough. This results in a more tender and flavorful piece of meat.
There are a few things to keep in mind when cutting beef against the grain. First, you need to identify the direction of the grain. This can be done by looking at the surface of the meat. The grain will appear as thin, parallel lines. Once you have identified the grain, you can start slicing against it.