Place all ingredients except the olive oil in a food processor or blender. Cover and process until the basil is finely chopped.
Add olive oil and pulse to combine.
Use pesto immediately, or store in an airtight container in the fridge or freezer.
Notes
Most recipes recommend that pesto be stored in the fridge for up to 1 week, or in the freezer for up to 3 months. I’ve kept pesto longer than that and it didn’t go bad, but the flavor changed over time—more savory, less herby. It still tasted great on a sandwich. :)
Recipe by I Wish I Was a Muffin at https://iwishiwasamuffin.com/basil-pesto-without-pine-nuts/