Break the bottom half of the stems off the cilantro and discard. Place all ingredients in the bowl of a food processor.
Lock the lid into place and puree until the mixture is very smooth. Taste, then add additional salt if needed.
Cover and refrigerate until ready to serve. Use within one week.
Video
Notes
Aji Amarillo Paste is an optional ingredient, but it does make the sauce taste more authentic. It is a simple puree of Peruvian yellow chile peppers. You can find Aji Amarillo online, and at most international markets.