Soak saffron in two tablespoons of warm milk and set aside. Boil half litre of milk. As it comes to a boil add lemon juice and keep stirring till all the milk curdles.
Strain the whey and tie up the chenna in a muslin cloth and dip in ice water till it cools completely. Then squeeze till all the liquid drains away. Set aside. Boil milk, add a pinch of saffron, reduce heat and let it simmer till reduced to half the original quantity.
Add sugar, stir and simmer till it dissolves. Mash chenna in a bowl. Add it to the milk. Simmer for two minutes. Add almonds and pistachios and the soaked saffron and take off the heat.
Cool and serve.