Spray with low calorie cooking spray, then mix well so that all the chicken pieces are coated. Cover and place in the fridge.
Preheat the Tefal OptiGrill - Turn the grill on, select the chicken programme and then press OK.
When the light turns blue and the machine beeps, this indicates that it is ready to cook.
Place the chicken strips on the OptiGrill and close the lid.
The indicator light will go through a series of colour changes to show the different degrees of cooking. When the indicator turns red and beeps, the chicken is ready.
Remove the chicken from the grill using tongs.
To assemble the shawarma, arrange a handful of iceberg lettuce on each wrap and divide the pickled cabbage between the two. Place the chicken on the pickled cabbage, then top with chopped tomatoes and onions.
Drizzle over some of the yoghurt dressing, roll up the wraps, cut each one in half and serve.