Place all of the ingredints as well as 1/4 cup olive oil into the food processor.
Turn the machine on and let it run for 1 minute.
Scrape down the sides. Add the additoinal 1/2 cup of olive oil if the pesto is still really thick and dry. I almost alwasys add in the extra amount.
Turn the machine on and let it run for another minute.
Spoon the pesto into an air-tighet conatiner and store in the fridge or freezer.