Prepare the chicken by cutting the boneless, skinless chicken thighs into bite-sized pieces and tossing them with cornflour, garlic powder, salt, and pepper until evenly coated.

Preheat your air fryer to 200°C (400°F) for about 5 minutes, then arrange the coated chicken pieces in a single layer and cook for 10-12 minutes, shaking halfway through.

Chop green and red peppers and onion into small squares while the chicken is cooking.

Heat olive oil in a wok or large pan over medium-high heat and sauté the chopped vegetables for 3-4 minutes until softened.

In the same pan, combine pineapple juice, light brown sugar, ketchup, and soy sauce, then bring to a simmer while stirring occasionally.

Prepare a slurry with cornflour and water, then stir it into the simmering sauce until thickened.

Combine cooked chicken, sautéed vegetables, and pineapple chunks into the sauce, and gently toss until coated.

Serve over rice or noodles, and garnish with sesame seeds if desired.