Pressure-cook the dal for atleast 3 whistle. Remove from the cooker and mash nicely. Add 2 cups of water to it. Fry the channa daal, red chilly, coriander seeds and coconut in 1 tsp of oil. Grind nicely into a fine powder. Chop the tomatoes into small piece’s (You can also grind it. Prepare tamarind water by soaking the tamarind in 2 cups of water and squeezing with hand.

In a saucepan add the tomatoes, green chilies, tamarind water, asafetida, salt and the rasam/sambar powder. Heat the contents of the pan thoroughly till it boils nicely. The raw smell of tamarind and the sambar powder should disappear. Add the daal water to the pan. Continue heating on low heat till you see small bubbles forming on the top.

Switch of the heat and add the ground masala powder to it. Do not let the rasam boil after adding the daal water. Heat oil in frying pan and add mustard to it. Once it stops spluttering add the karipatha to it. Add this to the rasam and garnish with coriander leaves. Serve hot with steamed rice.