The shoulder tender (also called mock tender and petite fillet) is a small, oblong muscle that rests on the cow's shoulder next to the top blade and is part of the chuck primal. The tender is made by separating the teres major muscle from the shoulder along the natural seam. Most of the fat and connective tissue has been removed leaving a lean piece of muscle. This cut of beef is cheaper, better tasting, and looks just like the tenderloin.
The shoulder tender needs some special attention, as overcooking will render the meat anything but tender. Cooking methods that are more forgiving, like braising, will deliver the best results. Marinades make grilling a viable option, oven roasting can produce a juicy dish, and advanced techniques like Sous Vide will guarantee a temperature-perfect product.