Indian
1Preparation
- Rinse the dal in a sieve several times until the water runs clear, then soak it in plain water for 20 minutes.
- Coarsely crush the black pepper, cumin seeds and garlic together in a mortar.
- Dissolve the tamarind paste in the 2 cups of water.
2Cooking
- Drain the dal and simmer it in a pot with 3 cups of water and the turmeric, lid ajar, until it falls apart and is very soft.
- Whisk the dal until smooth and set it aside.
- Put the tamarind water, tomatoes, salt and crushed spice mix in another pot and simmer until the tomatoes soften and the raw tamarind smell is gone.
- Add the mashed dal and heat gently until a light froth rises to the surface, then turn off the heat before it boils hard. If it looks thick, add a little hot water.
- Heat the ghee in a small pan, add the mustard seeds and wait until they start to pop.
- Add the cumin, dried chilies, curry leaves and asafoetida, stir for a few seconds until the leaves crisp and smell fragrant, then pour the tempering over the rasam.
3Serving
- Scatter the coriander over the rasam and cover the pot for 5 minutes so the flavours blend.
- Serve hot in bowls as a soup, or pour it over plain rice with a spoonful of ghee.
💡 Tips & common mistakes
- Common mistake: boiling the rasam hard after adding the dal — it loses its aroma and tastes heavy. Turn it off as soon as the froth rises.
- Rasam is much thinner than lentil soup — almost watery — so don't add extra dal.
- Crush the black pepper yourself right before cooking; old pre-ground pepper doesn't give the same aromatic heat.
🔁 Substitutions
- Toor dal: the same amount of split red lentils, which cook in only 15 minutes.
- Ghee: vegetable oil for a fully plant-based version.
- Tamarind paste: a lime-sized ball of block tamarind soaked in hot water, squeezed and strained.
