Add pine nuts to small skillet over medium heat and toast until golden brown. Set aside.
In food processor bowl, add half the pine nuts, 3 cups of the basil, 2 cloves garlic, 1/2 cup of the cheese, lemon zest, and lemon juice. Process for approximately 30 seconds or until the ingredients are finely chopped.
While the food processor is running, slowly drizzle in 3/4 cup of the olive oil and continue processing until a paste forms. Stop the food processor and scrape down the sides of the bowl.
Add remaining pine nuts, basil, garlic, and cheese to the bowl. Pulse until finely chopped.
Add salt and pepper (and adjust to taste), as well as any additional basil or garlic. Add remaining olive oil.
Store the pesto sauce in an airtight container in the refrigerator for up to 5 days, or put into ice cube trays and freeze. Store frozen cubes for using throughout the year.