Add 1 teacup of water to the China grass and cook on a slow flame until it dissolves completely. Strain.
Both the milk (keeping aside a little) and add the China grass, sugar and cardamom.
Warm the saffron, add the skim milk kept aside and mix until the saffron dissolves.
Add to the mixture and heat for 3 to 4 minutes.
Pour the mixture into an ice tray and put to set in the freezer compartment of a refrigerator.
To Serve, churn the solid ice-cream in a mixture to make it soft and fluffy.