The Guajillo is one of the most common and popular chiles grown and used in Mexico. It is mild to moderately hot, and has dark, reddish brown, leathery skin. The peppers range from 3-5 inches in length and are 1 inch wide. They are said to have either a green-tea flavor or fruity flavor, with hints of berries.
The Guajillo is usually sold in its whole, dried form, which can be either toasted and ground into powder, or re-hydrated and made into a sauce or paste. It may also be sold in its powder form, already ground down.
Guajillos, along with the Pasilla and Ancho, are used in traditional mole sauces. They are great in sauces, salsas and soups and chili, especially in the salsa for tamales. They can be ground down into a paste or a rub to add flavor to meat, or to make Harissa, a chili paste used in Tunisian cuisine. But, a little of this pepper goes a long way, so experiment first to see what level of flavor you prefer.