Drain and grind the rice to a coarse paste. Bring milk to a boil. Add rice paste dissolved in a little water or cold milk. Cook till rice is completely cooked, stirring constantly. Add saffron and mix well. Add sugar and cardamom powder and cook till sugar is completely dissolved. Pour into earthenware or china bowls and garnish with pistachios. Chill in a refrigerator for an hour before serving.