Fry thuvar dhall, 1/2 t.spoon cumin seeds, pepper, red chilli, and curry leaves in oil. Wet grind the above mixture. Bring 3 cups of water to a boil, and add tamarind paste, salt, and turmeric. Let this boil for a few minutes, and then add the ground masala. Fry 1/4 t.spoon cumin seeds, and 1 red chilli in ghee and add this to the rasam.