Get a muslin or cheese cloth and add yogurt in it. Tie together the edges of a chesse cloth and hung it for about 7-8 hours. Put the pan or a container under it to collect the excess drained water.
After 8 hours, untie the cloth and transfer the yogurt to another pan. This yogurt is called Chakka.
Add powder sugar to it and mix well. There should not be any lumps.
If you have Puran yantra, then add the Chakka and sugar in it. and blend it properly.
Add saffron, nutmeg powderor cardamom powder and give a quick stir. Garnish with slivered almonds. chopped pistachio.