Sierra steaks are similar to a flank steak, but are cut from under the chuck muscle (basically the shoulder), instead of the belly. It lies under the muscle from which Denver steaks are derived. Like flank, it's a tougher steak, but chock full of beef flavor. Marinade it and sear over high heat and let it rest under foil for 10 minutes and you'll have the perfect steak to share with the family. Be sure not to overcook it, or it will become tough.