Wash the basil leaves thoroughly and pat them dry.
In a food processor, add the basil leaves along with the pine nuts and garlic.
Pulse the mixture until finely chopped.
Scrape down the sides of the bowl with a spatula to ensure even blending.
Add the grated Parmesan cheese to the mixture.
With the food processor running, slowly drizzle in the olive oil until emulsified.
Stop and scrape down the sides again as needed.
Blend until the pesto reaches your desired consistency.
Season with salt and pepper to taste.
Transfer the pesto to a jar and cover with a thin layer of olive oil to preserve freshness.