2Place the tomatillos, onion, and garlic on a sheet tray.
3Broil everything until blackened and tender, keeping a close eye on them as cooking times vary (tomatillos around 17 minutes, onion about the same, garlic about 12 minutes).
4Transfer the chiles, onion, garlic, water, and seasonings to a blender and puree until almost smooth.
5Add the tomatillos to the blender and run the machine on low until desired consistency is reached.