A cross rib roast is a square cut of meat that is a bit thicker at one end, has two or three rib bones and has alternating layers of lean meat and fat. The cross rib roast comes from the chuck primal cut, which is the area of the cow between the neck and the shoulder and tends to be more tough. Chuck roast is cut from the cow's shoulder. It is a heavily exercised muscle, which gives the beef good flavor but it also makes it tough. Chuck is good for a pot roast or, when cubed, stew, because the connective tissue melts as the chuck braises and self-bastes the beef, making it very tender. Approximately 2.5 lbs.