Heat oil in a deep pan. Add mustard seeds and let splutter.Add chana dal and peanuts. Roast well. Now add onions and saute till tender. Then add coconut, red chili, coriander powder, turmeric powder, asafoetida and curry leaves and roast again until a fine coconutty aroma starts coming out. Now pour the tamarind water and salt and let boil until it comes to a thick consistency.
Turn off the flame and add steamed rice. Mix well without smushing up the rice. Keep covered and serve after 1 hour.