4 skinless, boneless chicken breasts, cut into chunks
spring onions, finely shredded, to serve
1 red pepper, deseeded and chopped into chunks
3 red chillies, 1 cut into chunks, 2 halved and deseeded
425g can pineapple chunks, drained and juice reserved
4 star anise
50g tamarind paste
100g caster sugar
100ml rice wine vinegar or Chinese vinegar
For the sauce, put the red pepper, chunks of chilli and pineapple juice in a pan and bring to the boil. Cover and cook for 10 mins, then puree in a food processor. Return to the pan with the pineapple chunks, chilli halves, star anise, tamarind, sugar and vinegar. Gently simmer for 20-30 mins until reduced and sticky. Keep warm, or reheat to serve.
Fill a large pan 1cm deep with oil and heat until shimmering. Whisk the soda water and 100ml cold water into the self-raising flour with a little salt. Tip the cornflour onto a plate, line a tray with kitchen paper and turn on the oven to low.
Stir the batter well. Dust the chicken with cornflour, then dip into the batter. One at a time, lower into the hot oil (about 5-6 every batch). Turn up the heat to keep the chicken frying, if needed, and cook for 5-6 mins, turning once. When cooked, drain on the tray, and keep warm in the oven. Repeat with the remaining chicken. Stack onto a plate with the warm sauce on the side, and scatter with shredded spring onions.