Fry chiles in a little canola oil until they just begin to darken and become fragrant. Or you can toast the chiles by placing them in a 275 degree F oven for 5 to 10 minutes or until they become fragrant; but do not allow them to scorch.

After frying or toasting the chiles, place them in a bowl, cover them with hot water, and soak them for 20 minutes. Remove the stems, seeds and veins, and place the chiles in a blender. Add just enough of the soaking liquid to blend the chiles to a paste. Strain the paste using a food mill.