Pinner says: If you enjoy cooking with a crockpot, this flank steak recipe is for you. Flank steak is a rather inexpensive cut a meat. If it is not prepared properly, it can be rather tough. This recipe is so easy and makes the most tender flank steak. I pop this in the slow cooker in the afternoon and forget about it until dinner time! This recipe has lots of kick! If you prefer a little less spicy, use half the green chiles.