1 pound (6 to 8 medium) tomatillos, husked and rinsed2 fresh chile peppers (serrano, jalapeno, etc..) or 1/2 tsp dried chipotle 1 small white onion, sliced 1/4-inch thick 4 garlic cloves, peeled Salt About 1 teaspoon sugar (optional)
Roast the tomatillos on a rimmed baking sheet about 4 inches below a very hot broiler until soft and blackened in spots, about 5 minutes per side. Cool, then scrape into a blender jar. I(f using dried chiles, heat a small (6-inch) ungreased skillet over medium, toast the chipotle, stirring until very aromatic, about a minute. Scoop into a small bowl, cover with hot tap water and soak for about 30 minutes, stirring from time to time to ensure even rehydration.) Turn the oven down to 425 degrees. Spread the onion and garlic on another baking sheet, slide into the oven and roast for about 15 minutes, stirring every few minutes until the onions are golden—they’ll look a little wilted with a touch of char on some of the edges. The garlic should feel soft and be browned in spots. Cool. Drain the rehydrated chiles or fresh chopped chiles (stems and seeds removed) and add to the blender along with the tomatillos and 3/4 cup water. Pick out the garlic from the onions and add it to the blender. (If all this is too much for your blender, blend in 2 batches.) Blend until nearly smooth. Roughly chop the onion, add it to the blender and pulse a few times until you’ve got as chunky (or smooth) a salsa as you like. Stir in enough additional water to give the salsa an easily spoonable consistency. Taste and season with salt, usually about 1 teaspoon, and the optional sugar.
adapted recipe from rickbayless.com