Put the basil, garlic, pine nuts, and parmesan cheese in a blender or food processor. Turn the machine on and drizzle in the lemon juice. Continue to puree until a smooth paste is formed. * The amount of garlic you use is a matter of personal taste. Also, some garlic is more pungent. So start perhaps with 2 medium cloves, then taste, and add more if, as I do, you like a strong, garlicky flavor. Makes 0.75 cup pesto