Dry roast all the ingredients for the rasam powder and grind them into a fine powder and keep aside.

Soak the tur dal in water for one hour and take it in a cooker pour 3/4 glass water and boil for 10 minutes and switch off.  After the pressure decreases remove the lid and take only the dal water into a dish.

Then wash the tomatoes and cut them into medium pieces and wash the tamarind with water and boil both in a dish and when the tomatoes get mushy switch off let cool and mash the tomatoes and tamarind thoroughly and filter the juice and keep it 

Now add this juice to the dal water add salt, turmeric and chili powder.  In a pan add oil and add tempering ( 1 tsp of mustard and cumin seeds, 1 tsp of channa and urad dal and 5 curry leaves ) when it starts to splutter add it to the tomato juice.

Boil the tomato and dal water on slow flame add the rasam powder and mix well and bring to a boil, let boil for 2 minutes and switch off, garnish with coriander leaves.  You can serve this hot with steaming hot rice and ghee, Yummy.