This stew is all about the deep red color and flavor of dried chiles. The larger peppers (guajillo, new mexico, pasilla) add an earthy fruitiness and mild spice, while the small chiles de arbol add some serious heat. Adjust the amount of hot chiles you use according to your preference (and tolerance) for spice.
Storage: Store leftovers in an airtight container in the fridge for up to four days. Or freeze for up to three months. If you opt to freeze, I like to use Souper Cubes to freeze into blocks. Once frozen, I transfer them to a resealable zipper-lock bag.