1.Mix a small lemon size tamarind in water. 2.cut one tomato and add it in water with little oil.bring to boil.smash it once bcom cold. 3.powder pepper,jeera and smash garlic and add to it. 4.In kadai,add oil,mustard,one red chilli.curry leaves,pepper jeera powder with garlic,turmeric powder,salt and add smashed tomato water and finnally add tamarind water.bring to boil. *dont boil too much as tomato is already boiled.boil rasam just for 1 min.finally garnish with coriander leaves.
it is my mother in law's way of preparation