2 half cups extra–virgin olive oil preferably from the "Italian Riviera", renowned for its sweet and fruity taste, which adds flavour to the basil and dressing.
The marble mortar and wooden pestle are the tools traditionally used to make pesto. Wash the basil leaves in cold water and dry them on a tea towel but don't rub them. In a mortar finely crush the garlic clove and pine nuts until they are smooth. Add a few grains of salt and the non–pressed basil leaves, then pound the mixture using a light circular movement of the pestle against the sides. Repeat this process.
When the basil drips bright green liquid, add the Parmesan cheese. Pour in a thin layer of extra–virgin olive oil, don't over do it. The preparation should be done as quickly as possible to avoid oxidation problems. In Genoa and Liguria each person has a secret to this recipe: you will never find two cups of pesto that are the same.