Put the basil, garlic, pine nuts and salt in a food processor and process until smooth. Gradually add olive to the mixture. Put the mixture into a bowl and mix in Parmesan cheese and black pepper to taste.
Serve with pasta or store covered in the refrigerator for up to a week. Freeze for longer storage.
I have read in more than one place that to keep the pesto refrigerated and fresh for later, smear the top with olive oil. I guess you could pour on a small amount of oil. Has to be enough to seal off the air.