Start by cooking moong dal. Dry roast split yellow moong dal in a pan for 3 to 5 minutes till light golden in colour. Take it in a bowl and wash it really well. Add it to pressure cooker and cover with 1.5 cup of water. Pressure cook for 2 whistle. Switch off the flame and let the pressure release by itself. Open the cooker and check whether the dal is cooked. Now the dal should be cooked completely and no water should be left in the cooker. Set aside till use.
In a separate pan add a tablespoon of ghee and roast sooji in ghee for couple of minutes till fragrant. Remove and set aside.
In a separate pot, add in cooked moong dal, along with 4 cups of water and salt. Mix this well and bring it to a full boil. Cook for 2 minutes.
Now reduce the flame, add in the roasted sooji, little at a time and keep mixing so no lumps are formed. Add in 2 tablespoon of ghee and mix. Cover and cook on low heat for 6 to 8 minutes.
Now in a separate pan, make tempering. Heat ghee, add in chana dal, pepper and cumin seeds. Allow it to sizzle, add in cashews and mix. Add in green chillies, ginger, curry leaves and asafoetida. Mix well.
Pour this tempering over the pongal and mix well. Add more ghee if required. Serve hot rava pongal with coconut chutney or sambar.