Put chicken in oven at 180degrees for 20-30 mins. Whilst the chicken cooking set your processor on the shredding option and shred the cabbage, lettuce and onion together, however if you dont have a processor u can grate the cabbage and slice the onion n lettuce or you can shred them by using a knife but do it very fine on the cabbage.
Put it all in a bowl and put the juice of the half a lemon, the sugar,salt and white wine vinegar in with the cabbage, lettuce and onion and mix it together a few times and taste to make sure its to your taste some people like more salt or lemon.
Leave on side in the bowl to absorb all the flavours until the chickens done.
Cut your pitta bread open and put in the microwave for about 30secs until warm and softish.
Place your pitta on a plate and mix the salad again and then put the salad in your pitta and slice your cooked chicken breast and place on top of the salad in the pitta too. if you like you can have some sliced cucumber or tomatoes too but i prefer it without. Also i get the heinz mayonaise to go with it, but it all depends what sauces you like.