1tablespoonTamarind**or 2-3 teaspoons ready-made tamarind paste dissolved in water.
1cupWater(Boiling hot) to soak tamarind
¼cupRed onionsliced
1Green chilislit
1 medium or ¾cupTomatoroughly crushed
2tablespoonsCilantro or coriander leaveschopped finely
¼teaspoonTurmeric powder
⅛teaspoonRed chili powder
Salt to taste
3cupsWater
For Tempering:
2teaspoonsOil
¼teaspoonMustard seeds
¼teaspoonCumin seeds
2Dried red chilies
6-7Curry leaves
Instructions
First take tamarind in a bowl and add hot water in that. Let it soak for 15-20 minutes.
Then squeeze and extract the pulp. Strain the mixture.
Using mortar and pestle, make the powder from black peppercorns and cumin seeds. Alternately you can use the spice grinder.
Now take tamarind water in a pan. Add sliced onions, crushed tomato, green chili and chopped coriander leaves.
Also add salt, red chili powder, turmeric powder and above prepared pepper-cumin powder.
Add another 3 cups of water and turn the heat on medium.
Adjust the water as per the sourness of your tamarind. So taste the tamarind water and if it is too sour then add more water, if less sour then add less water. So adjust accordingly.
Let it come to a boil and then simmer for 5-6 minutes. NEVER simmer for longer period of time. It should be simmered just till the rawness of tamarind goes away. By that time, onions will get soften.
Now heat the oil in a small tadka pan on medium heat.
Once hot add mustard seeds. Let them pop. Then add cumin seeds, let them sizzle a bit.
Now add dried red chilies and curry leaves. Saute for 40-50 seconds.
Immediately add to the rasam. Right away close with the lid. Let it rest covered for 5 minutes.
Notes
NEVER simmer for longer period of time otherwise it loses its flavor.
If serving alone, then I would recommend to strain it and drink only water part. If serving with rice then no need to strain it.