Tamarind Fish (assam Fish)

Pound the rempah ingredients to a fine paste in a mortar, or blend in a food processor.
Combine the tamarind pulp and water and leave to soften, then strain.
Coat the fish pieces in flour mixed with a little turmeric. Heat some oil in a frying pan and fry the fish pieces until lightly coloured. Set aside.
Heat a little more oil in a heavy-based saucepan and fry the rempah paste over high heat until fragrant. Add the lemongrass, tomato, chillies and tamarind water and bring to the boil. Season to taste with sugar and salt – the flavour should be a mix of hot, sweet, sour and salty. Add the fried fish and simmer over low heat for 5 minutes.