Put rice and ¼ cup milk in a mixer jar and grind coarsely.
Heat remaining milk in a non- stick pan, add the rice mixture and cook, stirring continuously, on medium heat till rice is fully cooked and the mixture thick.
Add 4 tbsps sugar and mix well. Add saffron and cardamom powder and mix well.
Heat oil and 1 tsp butter in another non-stick pan. Add almonds, pistachios and cashewnuts and sauté till light brown in colour. Add this to the phirni.
Add raisins to same pan and sauté for 15 seconds. Add this to phirni and mix well.
Transfer the phirni into a bowl. Add 1 cup mango puree, fresh cream and rose water and mix well. Set aside to cool. Refrigerate the phirni for an hour.
Put biscuits in a mixer jar, remaining butter and 1 tsp sugar and blend till smooth.
Put 2 tbsps of this mixture into each martini glasses and press lightly.
Top the glasses with chilled kheer. Garnish with 1 tbsp mango puree on top along with some chopped pistachios. Serve chilled.