1. In a pan, heat 1 tablespoon of oil. Put onion, cumin seeds and sauté for around 7 minutes till the onions turn light golden brown.
2. Add coconut and continue to sauté for another 5 minutes. Turn off the heat and allow to cool completely.
3. In a blender, add tomatoes, coriander powder and garam masala. Put the cooked onion mixture and blend till smooth.
4. In the pan, heat 3 tablespoons of oil and pour the blended masala into it. Add chilli powder and mix well.
5. Saute for few more minutes and cook till the oil begins to separate from the masala. Cover the pan partially to avoid hot splashes.
6. Pour water in it and bring it to boil. Cover and simmer for another 10 - 15 minutes and turn off the heat.
7. In a plate, serve the Rassa hot with patwadi. Garnish with coriander leaves if desired.
This rassa can be used to serve chicken or lamb or vegetables of choice.