pasilla chile
A dried chilaca pepper, long, narrow, almost black and wrinkled, with mild to medium heat and a flavour of raisins, cocoa and herbs.
Pasilla is the dried form of the chilaca, a long, slender Mexican chile; the name means roughly “little raisin” and refers to its dark, wrinkled skin. It is only mild to medium hot and tastes deep, slightly bitter and fruity, with notes of dried fruit, cocoa and liquorice, which is why it is used mainly in dark sauces, moles and soups, where it adds colour and depth. It is usually toasted briefly in a dry pan, soaked and puréed; toasted too long, it quickly turns bitter. You can find it in Latin American shops, well-stocked spice shops and by mail order. In North America fresh poblanos are sometimes mislabelled as “pasilla” in shops, but what is meant here is the dried black pod.
Substitute:
The closest are ancho (dried poblano) or mulato; both are similarly mild and dark but sweeter and less bitter, so the slightly bitter, herbal note of pasilla is missing. Chili powder or paprika are not a useful substitute, as they lack the body and depth.