Fry tuar dal, black pepper, red chillies, garlic and curry leaves. Make it into paste and keep it aside.
Make a paste out of the soaked tamarind. Add 2 or 3 glasses of water to this paste and allow it to boil for some time in a vessel.
Now add the grinded paste to it. Dilute the rasam by adding some more water. Let the rasam boil till everything mixes well.
Season the rasam with mustard seeds fryed in ghee.