Pressure cook dhal, separate dhal and dhal water. Keep it aside.
Heat ghee in a pan.
Splutter mustard seeds.
Add fenugreek seeds and red chillies.
Add garlic and fry on medium flame for 1 minute.
Add tomatoes and allow it to cook.
Add tamarind juice, cooked dhal, turmeric, pepper and cumin powder, asafotedia, salt, cilantro and curry leaves.
Allow the rasam to boil for 3 mins.
Finally, add dhal water and when the rasam starts to boil again, switch off the fire.