Sometimes the meat cut you want to buy isn't available for a variety of reasons. If this happens when ordering filet of sirloin, you have a few substitute options. Filet mignon is similar to filet of sirloin since it's also a lean, round cut. However, this option is a little more expensive. Other options that come with a slightly higher price tag are rib-eye and New York strip steaks, which share the juicy quality of filet of sirloin but have a little more fat. If you want a less expensive substitute, opt for either round steak or flank steak.