Heat 2 tbsp of oil in a heavy bottom pan.
Add mustard seeds and when they crackle, add red chillies and saute for a while.
Add crushed garlic and stir for a minute.
Add chopped tomatoes and salt and stir, till the tomatoes blend well.
Add turmeric and rasam powder and stir for a few seconds.
Add the tamarind paste and mix well.
Add curry leaves, coriander leaves and water.
Boil rasam on low flame for about 7 - 10 mins.
Finally, you can sprinkle asafoetida powder(optional).
:- Asafoetida is usually contained in Rasam Powder.
:- Serve rasam hot with rice.
:- You can also drink rasam like a soup.
:- Rasam is ready.