
Char in the oven. Turn the top broiler on in the oven and set a rack about 4 inches below the broiler. Place the tomatillos, peppers, and garlic on a baking sheet and broil for 5 minutes, then flip everything and broil 4 to 5 minutes more, until slightly charred and blistered. Let cool to the touch.
Pulse together. Transfer the tomatillos and peppers (see note below on heat level) to a food processor or high-powered blender. Peel the garlic and add that, along with the onion, cilantro, and salt. Pulse a few times, until your desired texture is reached.
Serve. Pour the salsa verde into a serving bowl and enjoy!