In a large pot, bring the rice and 8 cups of water to a boil. Skim off the foam as it rises. Cover and simmer for 35 minutes until the rice is soft.
Add 2 more cups water, as well as the sugar. Simmer for 25 minutes longer, stirring occasionally (be careful to not over-stir).
Grind the saffron and dissolve in a couple tablespoons of hot water.
Add the saffron water, corn oil, almonds, cardamom and rose water. Mix well, cover and simmer over low heat for about 20 minutes. Remove the cover and simmer over low heat for about 20 minutes longer, or until the rice has thickened to a pudding. Remove from heat.
Immediately spoon the Sholeh Zard into a large bowl or individual serving dishes.
Garnish with cinnamon, slivered almonds or slivered pistachios, if desired.