Peel, rinse, and quarter tomatillos. Rinse, stem, seed, and coarsely chop California chilies and jalapeños (use rubber gloves for jalapeños). In a food processor, whirl tomatillos, California chilies, jalapeños, onion, and cilantro until finely ground. Scrape into a 2 1/2- to 3-quart pan. Stir over medium-high heat until mixture releases some juice and is boiling, then reduce heat and simmer, stirring occasionally, to blend flavors, about 3 minutes. Let cool, then stir in lime juice and salt to taste.
Nutrition analysis per tablespoon.