Cut the chicken breast lengthways into 1 inch thick strips.
Cut the onion into quarters. Remove the smallest centre pieces.
De-seed the peppers and cut into large chunks, around 1 inch.
Place the chicken into a bowl, add the BBQ sauce (or other sauce) and then place into the fridge for a minimum of 1 hour.
Layer up your skewers. I like to do pepper, chicken breast, onion, pepper, chicken breast, onion and repeat.
I place the chicken on to the skewer in an "S" formation, which I achieve by skewering the bottom of the chicken strip, then the middle folded over, then I fold again and skewer the top of the chicken breast.
I place the skewers in to the Ninja Foodi kebab rack, into the air fryer basket and then air fry at 200C (390F) for 18 minutes. At the 10 minute mark I spray lightly with spray oil to keep them from becoming dry.
You can use wooden skewers if you don't have a kebab rack, or don't want to buy one, but soak them first to avoid them burning in the Ninja Foodi.