pesto the pride of the Italian province of Liguria, often particularly linked to Genoa, its chief city, is a thick sauce which is excellent with pasta or fish. It does not require cooking, but you add olive oil gradually to a mixture which you have pounded with a mortar; the pounded ingredients are garlic, pine nut kernels, grated pecorino and parmesan cheeses, salt, and fresh basil leaves. The flavour of basil is dominant and better grown in Liguria, they say, than elsewhere. Sometimes other nuts are used: walnuts, perhaps, or, in the small port of Camogli, hazelnuts. The sauce may be extended with ricotta when it is used with lasagne. A full discussion may be found in Plotkin (1997). The rage for pesto has spread far beyond its birthplace and manifold have been the variations, employing every sort of greenstuff, cheese, and piquant flavouring. In Provence it is called pistou and is added to a soup of that name. They may add grilled tomato to the mix and neither include cheese at the outset (merely stirring it into the soup at the end of preparation), nor have any nuts.
