Place basil leaves in small batches in food processor and whip
until well chopped (do about 3/4 cup at a time). Add about 1/3
the nuts and garlic, blend again.
Add about 1/3 of the Parmesan cheese; blend while slowly
adding about 1/3 of the olive oil, stopping to scrape down sides
Process basil pesto it forms a thick smooth paste. Repeat until all
ingredients are used, mix all batches together well. Serve over
pasta. Basil pesto keeps in refrigerator one week, or freeze for a few months.