Soak 100 grams of almonds in water for 4-6 hours or overnight. After soaking, peel the skin and grind them into a smooth paste using a little water or milk.
In a heavy-bottomed pan, heat 1 litre of full-fat milk and bring it to a boil. Keep stirring occasionally to avoid burning.
Once the milk starts boiling, reduce the heat and add the almond paste. Mix well and cook for 10-12 minutes, stirring continuously to avoid lumps.
Add 100 grams of sugar and a pinch of saffron strands soaked in 2 tablespoons of warm milk. Mix well and cook for another 10-12 minutes until the mixture thickens.
Add 1/2 teaspoon of cardamom powder and mix well. Cook for another 2-3 minutes.
Remove the pan from heat and let the phirni cool down to room temperature. Once cooled, pour the phirni into individual serving bowls or earthen pots.
Refrigerate the phirni for 2-3 hours or until chilled. Garnish with slivered almonds and saffron strands before serving.