Heat ghee in a cooker and roast the moong dal until fragrant. Add water, close and pressure cook for 3-4 whistles.
Open, mash and keep it aside until use.
Heat oil and ghee in a thick bottomed pan.
crackle mustard seeds and cumin seeds.
Further add chopped ginger, peppercorns, green chilli, curry leaves and cashews. Fry for a few seconds.
Measure and pour 3 cups water into the pan along with the cooked dal and salt. Let it come to a rolling boil.
At this stage, wither in rava little by a little while stirring continuously.
When its almost thick, add ghee and mix again.
Stop when it is thick. Put off the flame, close and let it sit for a few minutes before serving.
Serv the Pongal hot with chutney and sambar.