Cook thuvar dhall with turmeric, with 2 cups of water. Fry red chilles, corriander seeds, cumin seeds, 1 t.spoon thuvar dhall, hing, a pinch of mustard, cloves, cinnamon stick, and methi in oil. Wet grind the above mixture and keep it aside. Bring 3 cups of water to a boil, add tamarind paste, turmeric, and salt, and let this boil for a few minutes. Now add the ground masala and let it boil for 5-10 minutes, till the flavour comes out. Add the cooked thuvar dhall, and let it boil for 5-10 minutes. Heat some ghee, splutter mustard, then add a small pinch of cumin seeds, and curry leaves and add this to the rasam.