Mix all the marinade ingredients together in a bowl, add the chicken and season with salt and pepper. Mix well and place in a fridge for around 2 hours. Stirring occasionally.
Finely slice the red cabbage, drizzle with lemon juice and leave to one side.
Preheat the oven to 200°c.
For the sauce, place the garlic, onion and pepper on a baking tray, drizzle with oil and place in the oven for 30mins. Then add the tomatoes and chillies and cook for a further 15-20mins, until all charred.
Remove from the oven and leave to cool.
Remove the skin from the pepper, onion and tomatoes and squeeze out the garlic from 4 cloves and add to a blender with vinegar and olive oil. Blitz until smooth, place in a bowl and set aside.
Place the chicken on a hot grill (george forman or a griddle pan on a hob) and cook for around 5mins, turning over and then repeating until all cooked.
Warm the flatbreads, spread some chilli sauce over, topped with red cabbage, salad and grilled chicken