My aunt Marta Rojas of La Yerbabuena, Zacatecas, walked us through her approach to enchiladas—a food whose name, translated literally, means “in chile.” That’s the key to enchiladas' concentrated flavor: dipping the tortillas in a thick sauce made of (in this case) dried New Mexico chiles, garlic, cinnamon, and other seasonings. Rojas also includes a little chocolate, for added richness and intensity, and pulverized saltine crackers, which give the sauce terrific body. These are spare, unfussy, northern Mexican-style enchiladas, with just a scant filling of minced onion and crumbled queso añejo, a hard and pungent aged cheese; the art lies in the making.