How to Make It
In the bowl of a food processor (or large mortar and pestle), combine the tomatillos, peppers, onion, garlic, cilantro and 1 teaspoon of salt. Pulse until a chunky paste forms (don’t over-puree). Transfer the mixture to a bowl and add the lime juice. Fold in the avocado with a stiff whisk, mashing it as you go. Season to taste with salt.