Preheat the air fryer to 400°F (204°C) for 5 minutes. In the meantime, dice the chicken into 1-1.5 inches (2.54-3.8cm) chunks.
In a large ziplock bag, add the chicken, salt, garlic powder, and starch. Seal the bag and shake it to coat the chicken pieces evenly.
Spray the air fryer basket with avocado oil and place the chicken in a single layer into the basket with a little space between each piece. Spray more oil on top of the chicken.
Air fry for 8 minutes on the first side, open the basket, shake, spray with more oil, and cook another 2 to 4 minutes.
In the meantime, prepare the teriyaki sauce. Set it aside to cool to room temperature.
When cooking time is done, transfer the chicken to a large serving plate. Combine and toss with teriyaki sauce. Garnish with spring onions and sesame seeds. Serve hot.
Notes
Whey protein isolate: The chicken color is more golden orange than using starch. However, the chicken pieces tend to stick to the air fryer basket more than using starch.
Cook in 2 separate batches. Leave a little space between each piece.
Because the Teriyaki sauce adds extra salty flavor to the chicken, we intentionally season the chicken on the less salty side.
The nutritional label is estimated using keto teriyaki sauce and the chicken is dusted with tapioca starch.