Mix the marinade. In a mixing bowl, whisk together the soy sauce, brown sugar, rice vinegar, sesame oil, honey, grated garlic, grated ginger, and white pepper. The sugar will look gritty at first — keep stirring for about thirty seconds until the liquid turns a uniform dark amber and smells sharply of ginger and soy.

Coat the chicken. Pat the thighs dry with kitchen paper (this matters for browning), then add them to the bowl. Turn each piece with your hands or tongs until every surface is slicked with marinade. Leave them for 10 minutes at room temperature while you preheat the air fryer to 190°C.

Prepare the basket. Lightly brush the air fryer basket with neutral oil to prevent sticking. Lift the thighs out of the marinade, letting the excess drip back into the bowl, and arrange them in a single layer with a little space between each piece. Do not pour the used marinade over the chicken at this stage.

First cook. Air fry at 190°C for 12 minutes. Around the eight-minute mark you should hear a gentle sizzle and see the edges turning deep golden brown. If your air fryer runs hot, check at ten minutes.

Flip and glaze. Turn each thigh with tongs — the underside should be burnished and slightly crisp. Brush generously with the reserved marinade, then cook for a further 6–8 minutes until the internal temperature reaches 75°C and the glaze bubbles and darkens to a mahogany sheen.

Reduce the sauce. While the chicken finishes, pour the remaining marinade into a small frying pan with the cornflour slurry. Simmer over medium heat for 2–3 minutes, stirring constantly, until it thickens enough to coat the back of a spoon. It should look like warm honey and smell sweet and savoury at once.

Rest and serve. Move the chicken to a board and rest for 3 minutes — this lets the juices settle so they don't run out when you slice. Cut into thick strips, drizzle with the reduced sauce, and scatter over the sesame seeds and spring onions.