The chocolate in this sauce recipe is not sweet. You may not be able to find the right kind of dried chiles, unless you live in the southwest. Ancho chiles are brick red or darker, about 5 inches long and 2 -3 inches wide at the shoulder. It's medium hot, with underlying fuity flavor. Mulato chiles are dried Poblanos, the green form of the ancho, slightly larger, darker than anchos (no longer green when dried). Pasilla is very dark, almost black, wrinkled and tapered, only about 1 inch wide at the shoulder. Quite hot, underlying smoky flavor.