Combine all the ingredients except the olive oil in a food processor. Pulse until finely chopped, scraping down the sides a few times as needed.
With the food processor running, slowly pour in the olive oil until the pesto is smooth and creamy.
Add more olive oil or water as needed to reach desired consistency.
Transfer to a bowl and use as desired.
Notes
—Pesto will keep in the refrigerator in an air-tight container for up to 1 week.—Freeze the pesto in ice cube trays for longer storage. Once frozen, transfer to a freezer-safe bag for up to 6 months.