Remove the basil leaves and oregano leaves from their stems then place into a food processor with the remaining ingredients (besides the additionally tablespoon of extra virgin olive oil). Pop on the lid and blend well till a lovely pesto texture is reached. If you feel the pesto needs loosening up a little more then add the additional tablespoon of extra virgin olive oil. Taste and season again accordingly.
Place in an air-tight container and keep in the fridge for 1 week.