Set the Instant Pot on 'Saute' mode. Add the moong dal and rice to the pot and roast for 2~3 minutes or until fragrant. Turn off the instant pot and remove rice and dal into a sieve and wash well under water.
Return them to the Instant pot and add turmeric, salt and water. Set it on 'Manual/ Pressure cook' and cook on high pressure for 12 minutes. Let the pressure release naturally.
In the meantime, coarsely grind peppercorns and cumin seeds and set aside.
In a small pan, heat ghee and oil on medium heat. Add the freshly ground pepper-cumin powder, hing, grated ginger and curry leaves. Cook for 1~2 minutes or until fragrant.
Add this tempering to the cooked rice and dal. Mix well to combine.
At this point, if the pongal looks too thick, then add ½~1 cup of water to get to a porridge like consistency. Serve hot with chutney or raita.