Add the basil, toasted pine nuts, garlic cloves, salt, pepper, and parmesan to the bowl of your food processor (or blender). Pulse until the ingredients are incorporated.
With the food processor on, stream in the olive oil. I like my pesto a tad chunky, so I don't overdo it with the food processor. Taste the pesto, add salt and pepper to taste.
Pesto will stay good in the fridge for about 1 week.If you want to freeze the pesto, consider omitting the parmesan cheese, as it doesn't freeze well. Thaw the pesto, then stir in the grated parmesan cheese before serving.