In the bowl of a food processor, add the basil, the garlic, the pine nuts and the kosher salt. Using the on off switch, process the ingredients until minced.
With the processor running, slowly add the olive oil through the feed tube, in a thin stream until it is will blended. The pesto may seem a little thin but the cheese will thicken it up.
Transfer the pesto to a small container and then stir in the Parmesan. The pesto is now ready for use. If you are saving it for later, drizzle a small layer of olive oil on top, cover and refrigerate.
Pine nuts are expensive! Keep in mind that you should be able to get at least 4 batches of pesto with a 1 cup package. Just keep them handy in the refrigerator. You can use other nuts. Some people use walnuts or almonds. It will give the pesto a slightly different flavor but experiment with it. You may like it better!
Also, you can toast the nuts first before making the pesto. Adds a nice flavor.
Measuring out basil leaves seems tricky. Try not to worry about it. Fill your measuring cup as best you can, pressing down slightly to get some more in there. Sometimes you will have more and sometimes you will have less. Just adjust the amount of olive oil you add in, to get the consistency you want.