1 x (7 oz/200 g) packet creamed coconut
12 fl oz (350 ml) boiling water
2 tbsps olive oil
1 large onion, thinly sliced
1 garlic clove, peeled and crushed
3 fresh green chillies, deseeded and finely chopped
1 inch (2.5 cm) piece root ginger, peeled and grated
1 1/2 tsp ground cumin
grated rind and juice of 1 lime
1 1/2 lb (700 g) cod fillets, skinned and cut into 4 equal pieces