Roasted Hatch chiles are the most important ingredient for this recipe. You can purchase green chiles fresh or frozen online (find our favorite Hatch chile sources here), available in mild, medium and hot varieties. From July to October, some produce shops and farmers markets carry them fresh. As a substitute, use roasted Anaheim or other green chiles (but don't tell anyone from New Mexico).
These are rolled enchiladas—soft corn tortillas stuffed with shredded chicken and smothered with green chile sauce and cheese. If you prefer, make “stacked” enchiladas by layering tortillas, chicken, sauce, and cheese, as if making lasagna.