Tender lentils slow-simmered with warming turmeric, finished with a sizzling tarka of golden ghee, roasted cumin, and fresh coriander.
Crush the peppercorns, cumin seeds and garlic into a coarse paste.
Simmer the tomatoes with the tamarind pulp, salt and 3 cups water for 10 minutes until mushy; mash well.
Add the crushed paste and simmer 5 minutes without boiling hard.
Heat the ghee, pop the mustard seeds, and pour over the rasam.
Serve hot as a soup or poured over steamed rice.