In a food processor or blender, pulse together the basil, pine nuts and garlic 5 to 7 times, until finely chopped.
With the machine running, slowly drizzle in the olive oil. Scrape down the sides of the machine and add the cheese. Pulse a few more times to blend.
Serve immediately or store in a covered container in the refrigerator for up to 1 week.
You can substitute chopped walnuts for the pine nuts.
Romano cheese can be substituted for Parmesan.
To freeze, spoon the pesto into an ice cube tray and place in the freezer until completely frozen. Remove from the tray and place the cubes in a ziploc freezer bag, and freeze for up to 2 months. You can add to a cooked recipe from frozen, or thaw in the refrigerator overnight.