Place the pistachios in a bowl, cover with cold water and leave to soak overnight. Drain, and rub off the skins with a tea cloth. Put the pistachios and almonds in a blender or food processor and coarsely grind them. Do not over grind them. Break the vermicelli into pieces about 10cm (4inches) long. Melt the butter in a large saucepan, add the vermicelli and cook, stirring, until the vermicelli is nicely browned, without burning. Add the milk and cream, and bring to the boil. Reduce the heat, add the pistachio mixture, saffron, sugar and simmer for about 15 minutes, stirring frequently. Serve hot or leave to cool.