For the curry, first make the spice paste. In a blender, combine the seeds, onion, ginger, curry leaves, coconut, cumin seeds, peppercorns and a little water. Blend, adding more water if needed, until a smooth paste is formed.
To make the tamarind stock, place the pulp, stock and spices in a large pan and simmer for 20-30 minutes.
Heat a wok and add the spice paste. Once hot, add 200ml/7fl oz tamarind stock, the dates and coconut milk and cook for 4-6 minutes.
Heat the butter In a frying pan. Add the scallops and lobster, and cook the scallops on each side for 1-2 minutes. Stir the cooked seafood into the curry sauce and cook for a further 1-2 minutes.
For the rice, put the rice in a saucepan and season with salt. Pour cold water over the top until it comes 2cm/1in over the rice and cook for about 15 minutes, checking it doesn’t boil dry, until the water has been absorbed. Cover with a lid and turn the heat down low. After 5 minutes turn the heat off and allow the rice to steam until cooked to your liking.
Serve the curry in shallow bowls garnished with the cress. Place the steamed rice in separate bowls and top with the chopped coriander.