I thought I'd type up the recipe for my very favorite salsa, Diana Kennedy's Salsa para Barbacoa, from her Art of Mexican Cooking (p. 348). This is a fiery, tangy, smoky concoction intended to top barbecued lamb or goat but which goes wonderfully with any richly flavored meat or just served in a bowl with corn chips.
The recipe calls for dried chiles moritas, that is, red serrano peppers that have been smoked and dried, most familiar to American consumers canned in adobo sauce and somewhat misleadingly labeled as chipotles en adobo (actual dried chipotles, or smoked jalepenos, are a few inches long and a mottled tan color). What you should look for is small, sub-2-inch, coffee-colored dried chiles that, unless they are packaged totally air-tight, should smell very smoky. Ideally, the chiles should still be pliable and raison-soft, but if they have dried out some, they should still be fine.
To toast the chiles, heat a heavy skillet over medium heat. For most chiles, you want to press them into the pan to flatten them out, but that technique doesn't work too well with the often-brittle chiles de árbol and the often-lumpy chiles moritas that this recipe calls for, so I usually just throw them all into the pan together and toss them around for a few minutes. They're ready when the chiles de árbol turn a lighter shade and become quite brittle and when, an minute or two later, the chiles moritas soften and their skin begins to pucker slightly and discolor. They should give off a spicy, smoky aroma as they toast.
1 lb. tomatos verde, husks removed, rinsed
5-7 chiles moritas, toasted
10 chiles de árbol, toasted
2 garlic cloves, peeled and rough chopped.
2 tbsp. rough chopped white onion
1/4 tsp. dried oregano, ideally Mexican
1/8 tsp. cumin seed, toasted
3/4 tsp. salt
1.) Put tomato verde in a pan, cover with water, bring to a simmer, and cook for 5 minutes. Remove from heat, reserving cooking water.
2.) Crumble dried chiles into blender or food processor, removing about half the seeds as you do so. Add all remaining ingredients, except for the tomato verde, along with 1/2 cup of the reserved cooking water. Blend very thoroughly, until nearly smooth. (Some bits of chile skin will survive, but pay no mind).
3.) Add the tomato verde and blend briefly, just enough to break them up. It should retain a good deal of texture. Serve warm.