Use a molcajete for best results
Toast peppers (put them on a hot skillet, turning them as they blister, until they are evenly blistered). Remove papery outer skin of tomatillos and simmer until they turn from green to yellowish olive green (about 5 minutes).
Mash or blend garlic cloves. Add the peppers and the tomatillos. Add tomatoes. Add cilantro. Add salt and lime or lemon juice to taste.