Place the pork pieces in a bowl with soy sauce, Shaoxing wine, salt, white pepper, and egg. Mix well to coat evenly. Let it marinate for at least 20 minutes to absorb flavour while you prepare the sauce and vegetables.

In a separate bowl, combine cornflour and plain flour. Dredge each pork piece in the flour mixture until fully coated. Shake off excess flour for an even, crisp texture once fried.

Pour oil into a wok or deep pan until it reaches about 5 cm deep. Heat over medium to high heat to 180°C. You can test the temperature by dropping in a small piece of batter; it should sizzle and float immediately.

Fry the pork in batches to avoid overcrowding. Cook until light golden, about 3–4 minutes per batch. Remove and drain on a wire rack or paper towel. This first fry locks in the juices.

Increase the oil temperature slightly. Return the pork pieces for a second fry for 1–2 minutes until deep golden and extra crisp. Drain and set aside. This technique is essential for the classic crunch of Tang Cu Li Ji.

In a small bowl, whisk together ketchup, Chinkiang vinegar, sugar, soy sauce, oyster sauce, sesame oil, and water. Stir well until the sugar dissolves completely.

In a clean wok, heat 1 tbsp of oil. Add onions and peppers and stir fry over high heat for about 1 minute. Add pineapple chunks and cook briefly to keep the vegetables vibrant and slightly crisp.

Pour the sauce into the wok with the vegetables. Bring to a gentle simmer, then add the cornflour slurry to thicken. Stir continuously until the sauce becomes glossy and coats the vegetables evenly.

Toss the fried pork into the wok, stirring quickly to coat each piece in the sauce. The glaze should cling perfectly, giving the dish its iconic sweet and tangy aroma.

Transfer to a serving dish and garnish with a few sesame seeds or sliced spring onions if desired. Serve immediately with steamed jasmine rice. The contrast of crispy pork and glossy sauce is best enjoyed fresh.