Place pignolis and garlic in the bowl of a food processor fitted with a steel blade. Process for 30 seconds.
Add the basil leaves, salt and pepper. With the processor running, slowly pour the olive oil into the bowl through the feed tube and process until the pesto is finely puréed.
Add the parmesan cheese and purée for one more minute. Serve.
Can be stored in the refrigerator with a thin layer of olive oil over top, for up to four days.
Can be stored in the freezer with a thin layer of olive oil over top for up to 6 months.