For this rasam, we have to use raw thur dal. Instead of cooking the dal, we have to use as it is.
Ingredients:

1 tab sp Thur dal
1 – 1 ½ sp Tamarind Paste
1 – 1 ½ sp Rasam Powder

For Seasoning:

1 sp Mustard seeds
1 sp Cumin seeds
¼ sp Turmeric powder
1 Ripe Tomato
A pinch of asafetida
Salt
2 sp Ghee
Coriander leaves

Method:

In a pan make seasoning.
And pour 1 cup water and add ‘Tamarind paste’.
Mix well and add Rasam powder, turmeric powder, thur dal and asafetida powder.
Add cut tomato and salt.
Let it boil for 5 – 10 min.
At this time you add 1 cup water more in the rasam.
Bring it to a boil and remove from the fire and add coriander leaves.

Note: If you want you can make seasoning and add that to Rasam, after you complete the rasam. You can fry thur dal and add in the rasam.