Ingredients
1 lemon-sized ball tamarind paste (about 2 tablespoons)
1 1/2 teaspoons black peppercorns
3/4 teaspoon cumin seeds
1 pinch asafetida
1/2 teaspoon rasam powder
1/2 teaspoon grated or powdered jaggery (or brown sugar)
1 small tomato
5-7 fresh curry leaves
1 teaspoon ghee
1 teaspoon mustard seeds
1 tablespoon toor dal (split yellow pigeon peas)
Instructions
  1. Obtain a thin extract of tamarind by soaking and dissolving it in 1 cup (200 ml) of water. Discard any fibrous pulp.
  2. Dry roast the peppercorns, cumin, and asafetida in a dry skillet, stirring and tossing frequently over medium heat, until they begin to smell fragrant. Cool and grind into a fine powder.
  3. Stir the powdered spices, rasam powder, jaggery, and salt into the tamarind extract.
  4. Roughly crush the tomatoes and curry leaves and add them to the tamarind extract. Bring this rasam mixture to the boil.
  5. To this mixture, add 2 cups (400 ml) of water and continue heating until the rasam begins to foam.
  6. Heat the ghee in a small tempering or frying pan and add the mustard seeds. Once they splutter, add the toor dal and fry until the dal turns golden brown and aromatic.
  7. Pour this tempering into the hot rasam and stir through thoroughly.
  8. Sprinkle over a little cold water, cover and set aside.