Hang the yogurt in a muslin cloth for 3 hours, drain the whey and reserve.
Dissolve saffron in the milk and set aside.
Blanch the almonds, cool and cut into slivers.
Cut the pistachios into slivers and powder the sugar.
Tie a clean muslin cloth tightly over the mouth of a large clean vessel. The muslin cloth thus acts as a sieve and should not sag in the middle. Use a clean thick string to tie the cloth over the vessel. Transfer the thick yogurt along with the sugar onto the muslin cloth in small quantities.
For every cup of thick yogurt, add 3/4 cup of sugar.
Rub the above mixture firmly over the cloth, till the whole mixture is sieved.
Add the dissolved saffron, almonds, pistachios and cardamom power to the sieved mixture.
Mix well, transfer to a glass bowl and refrigerate till cold.