A slightly different version of this sauce exists in Provence, where it is known as "pistou". In contrast to "pesto alla genovese", "pistou" is generally made with olive oil, basil and garlic only: while cheese may be added, usually no nuts are included in a traditional "pistou" because no pine trees grow there to provide the nuts. "Pistou" is used in the typical "soupe au pistou", a hearty vegetable soup with "pistou" flavour. The sauce did not originally contain basil, however; instead, cheese and olive oil were the main constituents.