Tender lentils slow-simmered with warming turmeric, finished with a sizzling tarka of golden ghee, roasted cumin, and fresh coriander.
Boil the tomatoes with the crushed garlic, turmeric, salt, and water for 10 minutes.
Add the rasam powder and simmer 5 minutes until the rasam turns foamy on top, crushing the tomatoes with a ladle.
Heat ghee and pop the mustard seeds and curry leaves.
Pour the tadka into the rasam and simmer 1 minute more.
Serve hot as a soup or spooned over steamed rice.