Preheat the oven to 180°C. Heat the oil in a flameproof casserole over moderate heat. Add the onion and saute for 7 minutes or until tender. Add the cinnamon, cardamom, turmeric and a pinch of cloves, and cook for 30 seconds or until the spices are fragrant.
Stir in the rice, yoghurt, 2½ cups water and a pinch of salt, and bring to the boil. Cover and bake for 25 minutes or until the rice is tender. Stir in the sultanas and pistachios.