In a thick pan add water. Add diced tomatoes, jaggery and tamarind paste.
Bring the water to a boil. Then add cooked dal, ginger chili paste, turmeric and salt.
Boil the dal mix for 5-10 minutes, stirring intermittently.
In a pan add oil and heat it. Add urad dal and let it turn brown.
Then add mustard seeds, asafetida, cumin seeds, red or green chili and curry leaves. Once the seeds pop, turn down the heat.
Add rasam masala on the cooking dal.
Transfer the tempering on the masala and mix well.
Let the rasam cook for a couple of minutes, then turn down the flame.
Sprinkle cilantro on top and let the rasam sit for a few minutes.
Enjoy warm!