Inspect your basil for buggies. If you have any wash and dry thoroughly.
Pick the leaves off the stems.
Put the cheese, garlic, salt and walnuts in the bottom of a food processor. Place the basil on top.
Pulse 4-5 times to chop up the bottom ingredients.
Turn machine on continuous and add your EVOO through the hole at the time. Stop. Scrape and then process some more. The longer you process the finer it will be. Me? I like a few chunks.