1 tbsp Thai shrimp paste (from the world food aisle of supermarkets)
1¼ tbsp medium curry powder
1 tsp ground turmeric
1 tsp ground coriander
1 tsp ground cumin
1 tbsp fish sauce
Whizz the curry paste ingredients with 150ml water in a mini food processor. Set aside.
Heat the oil in a large, deep frying pan over a medium-high heat. Add the onions and fry for 5 minutes or until they start to soften. Add the curry paste and brown crabmeat, then cook for 10 minutes.
Add the coconut milk, half the lime juice, the sugar and fish sauce. Simmer for 5 minutes, then add the white crabmeat, prawns and cod.
Simmer for 5-8 minutes until the seafood is cooked through; stir gently and occasionally to avoid breaking up the fish. Add the coriander and remaining lime juice to taste, then serve with steamed rice, if you like.