Pasilla Salsa
When dried—as you will usually find them—pasillas are often called chile negro, or black chile. They are thin, small, shriveled, and very dark. They are also earthy and not especially hot, so they yield a rich, densely flavored sauce traditionally used with lamb, beef, and chicken. If you want some heat, soak a dried chipotle or two with the pasillas. If you can find fresh tomatillos, use them in place of the tomatoes. Slip off the papery husks and add a little water to the sauce.