Round knuckle steak is cut from the knuckle top sirloin. Knuckle steak can also be cut from the knuckle muscle piece, but in practice, this is rarely done. Van der Zee only cuts knuckle steak from the knuckle top sirloin. This comes from the rear part of the beef. It is a large piece of meat that is incredibly tender in texture. With this piece, you can go in any direction.