Take garlic in mortar pestle, roughly smash it with the skin. (Let the skin be in the rasam, it adds to the taste) transfer it to a plate/bowl.
Again take peppercorns, broken red chilli, fenugreek and cumin seeds in mortar pestle and roughly grind them.
Making Tamarind/tomato juice:
Boil roughly chopped tomato and tamarind until rolling boil. Smash it and filter it.
Making of rasam:
Heat 1 tsp oil in kadai, splutter mustard seeds, curry leaves and asafoetida. put in the ground mixture from step 2. saute for just half a minute. pour the tomato and tamarind water.
Add salt, turmeric powder, coriander powder, chopped coriander leaves. Mix well and let it boil. As soon it starts boiling, switch it off.
Notes
We can add 1 tbsp boiled dal and its optional.Adding a pinch sugar and a pinch of sambar powder to rasam always gives a special twist to it.