Halve new potatoes and parboil for 10 minutes, drain and set aside. Fry a tsp or two of mustard seeds in butter, until they start to pop,
then add sliced red onion and crushed garlic, together with the parboiled potatoes and stir over a high heat until the potatoes get a little
browned at the edges. Sprinkle over 2 tsp of turmeric, 2 Tbs tamarind paste and a half cup of water. Add a deseeded red chilli, and tomatoes,
skinned and cut into wedges, bring to a boil and simmer gently while you cook the fish. Lightly score the skin of sea bass fillets, season well
and fry in a little hot oil, skin side first, until nice and crispy, then flip over for another minute. Stir a Tbs of garam masala into the
potatoes and serve in bowls, garnished with coriander, topped with the fish.