This article is from the 20th Century Appetizer Recipes, with numerous contributions by known and also anonymous authors
All Quantities Approximate
8 To 16 Tomatilloes depending On size.
12 Chiles (2 Serranos + 2 Jalapenos + 8 Piquins) I
Typically use The serranos and jalapenos Green and the piquins red. 4 Cloves Garlic
1 sm Onion, really small, or half
Medium onion. 1/2 ts Salt
1/4 c Cilantro
Roast above ingredients in an oil-free cast iron pan, turning occasionally. Leave husks on tomatillos while you roast 'em. The husks will be nicely blackened, the skins translucent, and the fruits soft when they're done. (Let me add: the goal is to blacken the skin while doing the least tomatillo-exploding that you can. That way they don't lose juice into the pan, that burns and smells sometimes. That means moving them around the pan as they roast.)
Put roasted vegetables in food processor with: Salt 1/2 Teaspoon Cilantro 1/4 Cup and process briefly. Transfer to a pot, and cook the mixture for 5 minutes. This darkens it up a bit, and mellows the flavors. It tastes too raw otherwise.