Make the marinade by mixing all of the ingredients in a large bowl. Remove about a third of the marinade and chill.
Dice the chicken into bite-sized pieces
Stir the diced chicken into the marinade and leave for 20 minutes.
Soak some wooden skewers in water for about an hour.
Cut up all of the peppers and red onion into bite-sized pieces.
To make your kebabs, alternatively, thread a chicken piece, followed by a piece of pepper, followed by a piece of red onion, onto the wooden skewers. Repeat this process until all the chicken and vegetables are used up.
Cook on a hot barbecue for 10-15 minutes, ensuring the chicken is cooked through and lightly charred.
Serve your kebabs with the warm gluten-free flat breads, tomato wedges, yoghurt and lemon wedges