Pound the garlic with a pinch of salt and the basil leaves in a pestle and mortar.
Add the pine nuts and pound again.
Next, add half the parmesan. Stir gently and add olive oil – just enough to bind the sauce and get it to an oozy consistency.
Season with salt and pepper to taste.
Add most of the remaining cheese. Pour in some more oil and taste again.
Keep adding a bit more cheese or oil until you are happy with the taste and consistency.
Finally, add a squeeze of lemon juice and you’re done.