1. For the fishcakes, place the cod in a food processor. Pat the prawns with kitchen paper to remove excess water and add to the cod with the ginger, soy, rice wine and flour. Blitz to give a coarse paste. Stir in the salad onions and divide the mixture into 8. With wet hands, mould into 8 flat fishcakes. Chill until required.
2. To make the prawn toasts, pat the prawns with kitchen paper to remove excess water and add to the same food processor bowl used for the fishcakes. Add the chilli oil and most of the Thai basil, reserving a few leaves, and blitz to a paste. Spread onto the bread and sprinkle with sesame seeds. Cut each into 4 squares.
3. Heat 1 tbsp oil in a frying pan and fry the fishcakes for 3-4 minutes each side on a medium heat until golden and cooked through. Remove and keep warm.
4. Add more oil to the pan to give a 1cm depth and heat gently. Fry the prawn toasts in 2 batches for 1 minute each side until golden and drain on kitchen paper. Add to the fishcakes and keep warm.
5. In a wok, heat 1 tbsp oil and fry the onion for 3 minutes. Stir in the beansprouts and fry for a further 3 minutes. Stir in half the chilli sauce and heat through for 1 minute.
6. To serve, place the onion mixture on a serving platter and top with the fishcakes with the prawn toasts on the side. Shred the reserved basil leaves and scatter over the top. Heat the remaining chilli sauce and serve on the side.