Prepare the chicken: Pat the chicken thighs dry with kitchen paper. This is a crucial step — dry skin means better crispiness. Season the underside with a pinch of black pepper, but do not salt yet as the soy sauce provides plenty of saltiness.

Make the teriyaki sauce: In a small mixing bowl, whisk together the soy sauce, honey, brown sugar, rice vinegar, grated garlic, grated ginger, sesame oil, and black pepper. Stir until the sugar has completely dissolved. The mixture should smell pungent and sweet, with a sharp tang from the vinegar.

Marinate the thighs: Place the chicken thighs in a single layer in a shallow dish. Pour half of the teriyaki sauce over them, turning to coat each piece evenly. Cover and set aside for 10 minutes at room temperature. This brief marination is enough to infuse flavour without the acid starting to break down the meat’s texture.

Preheat the air fryer: Set your air fryer to 190°C (375°F) and let it preheat for 3 minutes. A properly preheated air fryer ensures the skin starts crisping immediately upon contact.

Air fry the chicken: Place the thighs skin-side down in the air fryer basket in a single layer, ensuring they are not touching. Cook at 190°C (375°F) for 10 minutes. After 10 minutes, flip the thighs using tongs — you’ll hear a satisfying sizzle and see the skin is golden brown and beginning to crisp. Cook for another 6 minutes.

Glaze and finish: While the chicken cooks, pour the remaining teriyaki sauce into a small saucepan and bring it to a gentle simmer over medium heat. Add the cornflour slurry and stir constantly. The sauce will thicken and become glossy after about 2 minutes — you’ll see it coat the back of a spoon. Brush this glaze onto the chicken thighs during the last 2 minutes of air frying. The glaze will bubble and set into a sticky, lacquered finish.

Rest and serve: Remove the thighs from the air fryer and let them rest on a cutting board for 3 minutes. The internal temperature should read 74°C (165°F). Sprinkle with toasted sesame seeds and sliced spring onions. The colour should be a deep, burnished mahogany, and the skin will feel taut and shatteringly crisp.