2 litres full-fat milk
2g crushed alum (available in stores selling Indian ingredients)
2 tsp ghee (clarified butter), for greasing
Pistachio slivers, to garnish
Bring milk to a boil in a large heavy-bottomed pan. Lower heat and simmer, stirring occasionally, until it thickens and begins to coat back of a spoon.
Add alum and stir continuously until milk becomes grainy and moisture evaporates.
Add sugar and continue to stir for about 10 minutes or until it becomes a solid mass.
Grease an aluminium tray with ghee and spoon mixture into the tray. Level with a spatula. Garnish with pistachio slivers and leave at room temperature to set. (Do not refrigerate as that would dry it up.)
When completely set, cut into desired shape and serve.