Sweet and Sour Pork Tenderloin

Trim and pat dry the 300 g pork tenderloin. Slice across the grain about 1 cm thick, then cut into strips about 5 × 1 × 1 cm. Keep the thickness even.

Put the strips in a glass bowl. Mix with 15 ml cooking wine, 5 ml light soy sauce, 1 g salt and 30 g egg white until slightly tacky. Cover and refrigerate for 15 minutes. The pork should remain raw and pink.

During marinating, stir together 45 g ketchup, 30 ml white vinegar, 30 g sugar, 5 g cornstarch and all 60 ml water in a small glass bowl. Reserve the remaining 60 g cornstarch for coating. Stir the sauce again before cooking because the starch settles.

Put the remaining 60 g cornstarch in a shallow bowl. Let free marinade drain from the strips, coat each strip and press gently, then shake off loose powder. Rest for about 2 minutes until the coating is slightly damp and adheres evenly. Keep the strips separate.

Add 500 ml oil to a deep wok about 22 cm wide. The oil must cover the strips and stay below half the wok's depth. Heat to 165–170°C and add the pork separately in 2–3 batches. Let the coating set before separating the pieces. Fry each batch for about 3–4 minutes until pale golden and cooked through; drain on a rack. Let the oil recover between batches.

Raise the oil to 185–190°C. Fry again in batches for about 30–45 seconds until golden with a firm, crisp crust, then lift out and drain immediately. Insert a thin probe from the side into a thick strip and check that the centre reaches at least 71°C; cook longer if needed. Colour and timing are guides.

Turn off the heat. Once safe to handle, transfer the excess frying oil to a heatproof container, leaving only 5 ml in the wok. Stir and add all the sauce from Step 3. Return to medium-low heat and stir for about 1–2 minutes until bubbling, glossy and able to coat the back of a spatula thinly; a trail across the base should close slowly.

Reduce to low heat. Add all the fried pork and toss for about 15–20 seconds, just until thinly coated, then turn off the heat. Do not simmer the pork in the sauce. Scatter over all 3 g toasted white sesame seeds and immediately transfer to the textured light-brown plate with a dark-brown rim. Serve hot.