Soak the rice in 2 cups water for 1 hour. Drain and pour the rice into a food processor. Grind until broken up but not powdered. Pour into a pot with 4 cups water and add the oil. Bring to a boil and cook 20 minutes, stirring continuously.
Mix 3 cups water, 2 cups coconut milk and the sugar in a bowl. Let stand to dissolve, 20 minutes.
Incorporate the sugar mixture and half the butter to the rice, stirring over medium heat. After 5 minutes, add the remaining 2 cups coconut milk, the remaining butter, the saffron and rose water. Simmer until the rice is cooked and has a thick consistency, 15 more minutes. Remove from the heat and pour into a serving bowl, stirring to cool. Place in the refrigerator for 4 hours to set. Garnish with pistachios and candied orange peel.