Chihuacle negro chiles are my favorite of all dried chiles. They look a little like black bell peppers and have an amazingly subtle and complex flavor. If you can’t find them, substitute other dried chiles, such as guajillos, mulatos, or anchos, either alone or in combination. Or use fresh poblano chiles—first char their skins over the stove or on the grill, then peel, seed, and chop them.
The sauce I describe here is made with concentrated duck broth, which gives it a note of richn