Crush garlic and chop tomatoes.
Soak the tamarind and extract the pulp.
Roast the ingredients for the powder and grind until fine.
Boil the dal with tomatoes till the lentils are mashed and set aside.
Heat oil and add mustard seeds, leave until it crackles.
Add the crushed garlic, curry leaves and the coriander leaves.
Mix the dal and water to get the required rasam consistency.
Mix in the tamarind pulp. Add the rasam powder.
Boil for 5 minutes on a low flame.