
This crispy sweet and sour chicken delivers crunchy fried chicken with a glossy, tangy pineapple sauce that tastes better than takeout. Red pepper, chili, tamarind, and vinegar give the sauce depth, while the light batter keeps the chicken crisp and golden.
Make the sauce base: add the chopped red pepper, the chopped chili pieces, and the reserved pineapple juice to a saucepan. Bring to a boil, then cover and simmer for 10 minutes until the pepper is very soft. Blend until smooth.
Return the blended sauce to the pan and add the pineapple chunks, halved chilies, star anise, tamarind paste, sugar, and rice wine vinegar. Simmer gently for 20 to 30 minutes, stirring occasionally, until the sauce is thick, glossy, and slightly sticky. Keep warm.
Pour enough oil into a large deep frying pan to come about 1 cm up the sides. Heat over medium-high heat until shimmering. Meanwhile, whisk the self-raising flour with the chilled soda water, cold water, and salt until you have a smooth batter.
Spread the cornflour on a plate and line a tray or plate with paper towels. Heat the oven on low to keep the cooked chicken warm. Lightly coat the chicken pieces in cornflour, then dip them into the batter.
Fry the chicken in batches, lowering in a few pieces at a time so the pan does not get crowded. Cook for 5 to 6 minutes, turning once, until the coating is crisp and the chicken is cooked through and golden.
Transfer the fried chicken to the lined tray and keep warm in the oven while you fry the remaining batches. If needed, adjust the heat between batches so the oil stays hot but does not smoke.
Pile the crispy chicken onto a serving plate and serve with the warm sweet and sour sauce on the side, or toss lightly just before serving. Finish with shredded spring onions.
For extra crisp chicken, make the batter just before frying and keep the soda water cold. The sauce can be made up to 2 days ahead and reheated gently. If you want a milder flavor, reduce the chilies or remove all seeds before cooking.