Turn on the saute mode of Instant Pot on high and add ghee when it displays hot. Add asafoetida and cumin seeds/ jeera and mustard seeds/rai and curry leaves.
Add finely chopped onions and saute till light pink. Add tomatoes and cook till soft and mushy.
Add turmeric powder, sambhar powder and red chilli powder and mix.
Add soaked rice and lentils. Add salt to taste and 3-4 cups of water.
Cancel the saute mode, set the pressure cook mode on high for 10 minutes.
Once the timer goes off, after 5 minutes, release the pressure from the and open the lid. Check for the doneness of the rice and lentils. Adjust the consistency of water if the rice is thick.
Add the tamarind pulp or paste.
Mix it and cook the rice for another 4-5 minutes.
Prepare the tempering. In a pan, heat some desi ghee or oil, when it is warm enough, add cumin seeds,mustard seeds curry leaves, when it splutters, add the dry red chillies and some onions. Fry onions till light pink. Add red chilli powder if required , add to the Sambhar Rice and serve it hot!!