Soak tamarind in 1/2 cup of water and extract the juice.
Next heat a tbsp of oil in a pan. Add in mustard and cumin seeds. Optionally you can add few methi seeds.
Wait until mustard seed splutters. Add in slit green chillies and curry leaves.
Followed by add in asafoetida.
Also add in turmeric powder.
Reduce the flame and add in tamarind juice.
Add in salt as per your taste.
Add in jaggery. Adjust salt and jaggery level as per your taste.
Bring it to boil. And continue boiling for few minutes.
At the end add in saarina pudi or rasam powder. Please note, adding rasam powder is optional.
Mix well, boil for a minute and switch off the stove. Serve it with either rice or pongal.