First peel the garlic. Next, rip the basil leaves off the stalks and place them in a mortar along with the garlic. Add a sprinkling of pine nuts and some salt. Bash the mixture together until it becomes a paste - the salt will help to break everything down. Grate in a bit of Parmesan, but not too much as you can always add more in at the end. Drizzle in enough oil to make it more like a sauce. Virgin olive oil is the best for this as it has a good flavour. Season with some freshly ground black pepper and serve.