Prepare the Chicken Coating: In a medium bowl, whisk together the plain flour, 60g cornflour, salt, and white pepper. In a separate shallow bowl, lightly beat the egg.

Coat the Chicken: Pat the chicken pieces dry with a paper towel. This is a crucial step for a crispy coating! Dip each piece of chicken first into the beaten egg, letting any excess drip off, then dredge it thoroughly in the flour mixture. Place the coated pieces on a plate or baking tray.

Fry the Chicken: Pour the vegetable oil into a large frying pan or wok until it's about 2cm deep. Heat over a medium-high heat until it shimmers (around 175°C). Carefully add half of the chicken pieces, ensuring not to overcrowd the pan. Fry for 5-7 minutes, turning occasionally, until golden brown and cooked through. Remove with a slotted spoon and drain on a wire rack. Repeat with the remaining chicken.

Make the Sauce: In a small jug or bowl, whisk together all the sauce ingredients EXCEPT for the cornflour slurry: the reserved pineapple juice, rice vinegar, brown sugar, ketchup, and soy sauce. Set aside. I find that mixing the sauce while the chicken is frying is the most efficient way to manage time.

Sauté the Vegetables: Carefully pour out most of the frying oil from the pan, leaving about 1 tablespoon. Return the pan to a medium-high heat. Add the onion and bell peppers and stir-fry for 3-4 minutes until they are slightly softened but still have a bit of a bite.

Simmer and Thicken Sauce: Pour the prepared sauce mixture into the pan with the vegetables. Bring it to a gentle simmer. Once simmering, slowly whisk in the cornflour slurry. Continue to cook for 1-2 minutes, stirring constantly, until the sauce has thickened to a glossy consistency that coats the back of a spoon.

Combine and Serve: Add the drained pineapple chunks and the crispy fried chicken to the pan. Gently toss everything together for about 1 minute until the chicken and vegetables are fully coated in the luscious sauce. Serve immediately, garnished with sliced spring onions and toasted sesame seeds.