The dried form of the poblano, ancho chiles are one of the "holy trinity" (together with the mulato and pasilla) used to make many of the myriad traditional Mexican mole sauces. Mildly sweet with a plum-like flavor, ancho chiles won't overpower dishes with too much heat. Traditionally pureed and used in sauces, anchos also add interest to soups and salsas.
This is one of those fabulous recipes born from what happened to be on hand one night. Pumpkin Kale Enchiladas are a delictable dish that probably couldn't have come about any other way.