Boil milk in a non-stick pan.
Grind rice with a little hot milk. Add the ground rice to the boiling milk and cook for 5-7 minutes, stirring continuously. Transfer the mixture into a bowl and set aside to cool.
Cook sugar with 2-3 tbsps water in another non-stick pan. Roughly chop plums and prunes and add to the pan.
Add green cardamom powder and mix well. Cook for 5-6 minutes. Transfer into another bowl and set aside to cool.
Reserve some of the plum mixture for garnishing and add the remaining to the rice-milk mixture and mix.
Transfer into serving bowls. Spread the remaining plum mixture over the phirni. Garnish with almond and pistachio slivers and serve chilled.