Sweet-and-Sour Crispy Fish

Make 4-5 deep cuts into the flesh on each side to allow the deep-frying oil to penetrate it: lay the fish on its side and cut down into the thickest part of the fish near the backbone, about 2-inch (5cm) from the base of the fish head and at right angles to the backbone itself. When the knife touches the bones of the spine, swivel the blade inside the flesh to face the head and continue cutting parallel to the backbone and towards the head for about another 1.25-inch (3cm). This will create a thick flap of fish flesh. Make further, similar cuts at 2-inch (5cm) intervals until you reach the thinner tail flesh, and then repeat on the other side of the fish, again cutting down to the spine and back towards the head. (When you have finished, if you hold the fish upside down by its tail, the flaps should all hang outwards slightly.)

Splash the fish with the Shaoxing wine and then rub it all over, including inside the flaps and the gut cavity, with the salt and white pepper for the marinade. Stuff all the ginger and green onion into the gut cavity and the flaps. Leave the fish to marinate for about 30 minutes.

Slice the green onion into thin strips. Chop the cilantro. Soak them in a bowl filled with water.

Remove the seeds of the pickled chillies. Slice them into thin strips. Soak them in water.

Mince the garlic, ginger, green onion, and set aside.

Discard the ginger and spring onion pieces from the marinated fish, and wipe it dry with kitchen paper or a clean towel.

Smear the fish generously inside and out with cornstarch (about 5 tablespoons).

In a separate bowl, mix 2/3 cup (100g) of potato flour with enough water (a bit less than 2/3 cup / 100ml) to make a fairly thick but still drippy paste. Assemble the other ingredients near the stove, and make sure your serving dish is to hand.

Heat plenty of deep-frying oil over a high flame to about 350°F/180°C. When the oil has reached the right temperature, hold the fish up by its tail and coat it with the potato-starch paste, using your fingers to push it into all the crevices. The flaps of flesh should hang outwards slightly, laden with paste. Then, still holding the fish by its tail, lower the head into the oil and allow it to fry for a couple of minutes as you ladle hot oil over the body of the fish and into the flaps. When the oil has fixed the flaps in their open position, standing stiffly out from the body, immerse the fish totally in the oil and fry for another 3-4 minutes until the batter is crisp and golden. Carefully remove it to your serving dish.

Combine the sugar, black vinegar, Shaoxing wine, soy sauce, chicken stock, and cornstarch slurry in a small bowl for the sauce.

Pour off the deep-frying oil, give the wok a quick rinse and return it to a high flame. Add 3 tbsp of oil. When the oil is hot, add the garlic, ginger and greeb onion and stir-fry until they are richly fragrant. Give the prepared sauce ingredients in the bowl a stir, add to the wok, stir briskly, and bring the sauce to the boil until the liquid thickens.

Reheat the deep-frying oil, then re-fry the fish for less than 1 minute. Place the fish on a serving plate.

Pour the sauce all over the fish. Sprinkle with the garnish ingredients and serve.