in a large kadai heat, 3 tsp oil and splutter 1 tsp mustard, ¼ tsp methi, ½ tsp cumin and few curry leaves.
add in prepared masala paste and saute for a minute or 2.
now add 1 tomato, 1 cup tamarind extract, ¼ tsp turmeric, ½ tsp jaggery and 1 tsp salt.
cover and boil for 10 minutes on medium flame.
now add reserved kollu extract (cooked horsegram water) and mix well.
boil for 2 minutes making sure the flavour is absorbed.
finally, add coriander leaves and enjoy kollu rasam with hot steamed rice and kollu sundal.