Method
Skin the pistachio nuts. Finely grate the parmesan. Wash and dry the basil and parsley. Peel and coarsely chop the garlic. Put the basil, parsley, pine nuts, walnuts, pistachios, parmesan and garlic in a food processor. Add half the oil. Work until the ingredients are finely chopped. Gradually add the remaining oil through the feed tube with motor running. Season to taste. Process again briefly.