Ingredients
A large piece of jaggery, melted in the microwave
1 cup brown sugar(or ordinary white sugar)
1 cup freshly squeezed lime juice
1 tsp powdered cardamom 
10 cups of cold water

Method
Add all the above ingredients to the cold water and 
adjust the water content/sugar content to suit taste.
Mix well till you everything is dissolved and you get
a clear solution.
Serve chilled, garnished with a mint leaf.
Very good in the summer.