Preheat the broiler and arrange peppers, onion, and garlic on a small cookie sheet. Broil until starting to char on one side, then flip peppers over and char the other side. Allow to cool then cut off pepper stems. Remove seeds if desired. *Alternatively, use a grill, grill pan, air fryer, or oven.

With the food processor running, drop garlic cloves and onion pieces through the feed tube. Chop well, then add the peppers one at a time. Stop the machine and scrape down the sides of the bowl. Add the cilantro to the bowl and pulse to chop. Pour in the lime juice and olive oil, pulse until smooth, then taste for seasoning and add salt as needed.