1. You can replace coconut milk instead of milk.
2. If doing so, take a thick extract of coconut milk of 1/2 cup and add to the Paruppu payasam, after switching off the flame.
3. You can add some more milk if the consistency of the paruppu payasam is too thick.
4. Do not hot milk to the payasam, it will curdle.
5. Also when the jaggery paruppu mixture is hot, do not add milk.
6. Paruppu payasam tastes nice when chilled.