First, wash and chop the tomatoes into cubes and puree them with a blender. Place it aside for use later.
2 tomatoes - puree
Grind the black pepper and cumin seeds in a little (coffee) grinder and make them into a coarse powder. If you don't have a coffee grinder, you can use a mortar and pestle to get it done.
1 teaspoon black pepper, 1 teaspoon cumin seeds
Place a medium-sized vessel on medium heat and add 2 teaspoons of coconut oil.
As the oil heats up, add mustard seeds and urad dal. Saute until mustard seeds start to crackle.
½ teaspoon mustard seeds, ½ teaspoon urad dal/split black gram
Add curry leaves and green chilies to the pot and saute it for 30 seconds.
6 curry leaves, 2 green chilies sliced
Add the tomato puree, turmeric powder, and tamarind paste and mix well. (If you are using tamarind pulp, soak it with ½ cup of warm water for 5-10 minutes, extract the tamarind essence and add it to the pot.)
1 teaspoon tamarind paste, ¼ teaspoon turmeric powder
Add 2 ½ cups water and salt. Give it a nice stir.
Add powdered black pepper, cumin seeds and stir well.
Once it starts boiling, simmer it on a low flame for 10 minutes until the raw smell of the tamarind disappears. By this time, the rasam quantity would have reduced a little. Add ½ cup water if the dish is too thick.
As you continue to simmer, froth starts forming on the top indicating the time to turn off the flame. Garnish with chopped cilantro.
2 tablespoon cilantro chopped