Tender lentils slow-simmered with warming turmeric, finished with a sizzling tarka of golden ghee, roasted cumin, and fresh coriander.
Grind the soaked urad dal with the green chilies into a thick, fluffy batter, whisking in salt.
Drop spoonfuls of the batter into hot oil and fry small round vadas until golden.
Simmer the tamarind pulp and tomatoes with the crushed pepper, cumin, salt, and 3 cups water until the raw smell fades.
Sizzle the curry leaves in the ghee and pour the tempering into the rasam.
Drop the hot vadas into the simmering rasam and let them soak for 10 minutes.
Serve the rasam vadas warm.