1. Pick over, wash and put the rice to boil in the water in a large saucepan over medium heat until very soft, adding more water as required and stirring from time to time. (Be careful it doesn't boil over.)
2. Stir in the sugar, rose water and saffron and simmer till sugar is dissolved.
3. Reduce heat, melt the fat and stir in. Cover and simmer for three minutes.
4. Dish up into a serving bowl. when set, decorate with powdered cinnamon and, if desired, almond and pistachio slivers.