take a lemon sized tamarind and soak it in water for 15-20 minutes. crush it well with hands to extract the pulp and keep the tamarind water ready.
take 3 large local tomatoes, cumin seeds, peppercorns, coriander seeds, red chillies, curry leaves, chana dal, fenugreek seeds and grind it to coarse paste.
heat coconut oil in a pan. crackle mustard seeds and then add crushed garlic, crushed small onions, curry leaves and turmeric powder. fry for 5 seconds.
immediately add the ground paste, tamarind water and salt.
add more water if required to thin the consistency of rasam. I used 2 cups to make tamarind water. 1 cup extra plain water. further add asafoetida a pinch, rasam powder
lastly, add jaggery mix well and let it come to a rolling boil.
when it reached the rolling boil, add chopped coriander, mix well and switch off. IMMEDIATELY CLOSE THE VESSEL. capture the flavour within. serve hot with rice and poriyal.