Chuck steak is a cut of beef and is part of the sub primal cut known as the chuck. The typical chuck steak is a rectangular cut, about 1″ thick and containing parts of the shoulder bones, and is often known as a “7-bone steak”. (This is in reference to the shape of the bone, which resembles the numeral ‘7’, not to the number of bones in the cut.)
This cut is usually grilled or broiled; a thicker version is sold as a “7-Bone Roast” or “chuck roast” and is usually cooked with liquid as a pot roast. The bone-in chuck steak or roast is one of the more economical cuts of beef.
In the United Kingdom, this part is commonly referred to as “braising steak”. It is particularly popular for use as ground beef, due to its richness of flavor and balance of meat and fat.