Wash and pressure cook the dal along with salt, turmeric, peanuts and water with 2 whistles and simmer for 5 minutes.
In a pan, heat 1 tablespoon oil. Add tomatoes and add the dal. Bring to a boil and switch off the gas.

In a tadka pan, heat remaining oil.
Add mustard seeds, cumin seeds, hing, curry leaves, red chillies, pinch of turmeric and mix everything well.
Now add this tadka to the dal and serve hot with steamed rice or rotis.