Put the basil into your food processor fitted with the metal blade, pushing it down to fit, if necessary.
Add the rest of the ingredients on top. Pulse the machine 20 times. Then scrape down the sides.
Pulse the machine 20 more times, and scrape again.
Run the machine for about 5 seconds. Scrape again. Give it a taste to make any adjustments to the ingredients.
Run for a final 5-10 seconds, at most. The pesto should be perfect.
Transfer to an airtight container and refrigerate until needed.
Notes
I use extra virgin olive oil, but it may be too strong for some. I recommend a mild style olive oil for a less bitter flavor.Your pesto will last about a week in the fridge. Freeze for longer storage.