mulato chile
A dried pod from a poblano type that ripens to a deep brown, broad and leathery, with a dark, sweetish flavour and mild heat.
The mulato chile is the dried fruit of a poblano variety that is left on the plant until it ripens to a dark brown, then harvested and dried. It is a close relative of the ancho but tastes darker and less fruity, with notes of chocolate, tobacco, prunes and a faint hint of liquorice. Its heat is mild to medium, so its main contribution to sauces, moles above all, is colour, depth and body. The pods are usually seeded, briefly toasted in a dry pan, soaked and puréed. Look for them in Latin American grocery stores and from online suppliers of Mexican ingredients; outside North America they rarely appear in ordinary supermarkets.
Substitute:
The closest substitute is the ancho, which comes from the same plant type; it is a little fruitier and lighter, so the sauce turns out less dark and less bittersweet. Adding a pasilla chile partly makes up for the missing depth, though it does not fully reproduce the mulato's own chocolate-like character.