Turn on the instant pot to saute mode and add the ghee. Once the ghee gets hot add cashew and fry till pale brown. Remove and set a side for later.
Then add cumin seeds, green chili, ginger, curry leaves and crushed ( or whole) black pepper corns. Saute for 30 seconds.
Add the oats, yellow moong dal and hing and saute for a minute ( not more than that)
Cancel the saute mode, add salt, turmeric powder and water. Give a mix.
Close the lid with the vent in the sealing position. Press pressure cooker mode and adjust the time to 8 minutes.
Once the pot beeps, wait for the pressure to release naturally.
Give a mix, taste and adjust the salt. Drizzle some ghee and top it with the reserved cashew and enjoy oats pongal piping hot.