Cube steak is usually a top round cut, tenderized by specialized cube steak machines that make a series of small cuts with a bladed roller. The name refers to the shape of the indentations left by that process (called "cubing"). This is the most common cut of meat used for chicken fried steak. It also makes a great breakfast steak. It can be tough if over cooked. It's best when rare and juicy. U.S. raised grass-fed beef.