Also in parallel, soak the tamarind in warm water along with salt (about 2 tsp) for atleast 15 minutes. Then extract the tamarind juice and make it to measure five cups by adding sufficient water. Add the whole tomato, turmeric, asafoetida, sambar powder to the tamarind extract and mix nicely with your hands. Crush the tomato, making sure that the tomato gets mixed well with the tamarind extract.