This is an intense chile sauce traditional to Mexico. We've relied on two dried chiles that are easy to find: the pasilla, which is long, dark brown, and mild; and the ancho, which is heart-shaped, dark brown, and mild. You can use only one, if it's all you can find, but the combination of the two results in a more balanced flavor.
2 pasilla chiles
1 ancho chile
4 cups boiling water
How to Make It
Remove stems and seeds from chiles. Combine chiles and boiling water in a large bowl; cover and let stand 30 minutes or until soft. Drain chiles in a colander over a bowl, reserving 2 tablespoons soaking liquid. Combine the chiles and reserved soaking liquid in a blender, and process until smooth. Cover and chill.