To make the kebab mixture, add the dry ingredients to a large bowl and mix well. Make a well in the centre and add the liquid ingredients. Stir everything together really well to combine.
Turn the dough out onto a flat surface or board and knead well for at least 5 minutes, until the dough is smooth and springy.
Lay a sheet of foil on top of a sheet of greaseproof paper on a flat surface. Lay the kebab dough on top and roll into a large sausage shape, twisting at the ends to seal
Place the kebab in a large pot, cover with water and bring to a simmer. Cover with a lid and cook for 1 hour, checking the pot doesn’t boil dry. After cooking time is up, leave to cool in the foil wrapping.
Place the red and white cabbages in 2 separate bowls. Sprinkle each liberally with salt and a squeeze of lemon juice, and set aside to soften slightly.
When ready to serve, finely slice the kebab and stir fry briefly in a little oil over a high heat, until piping hot and starting to become slightly crisp at the edges. Pile the pittas high with the lettuce, tomato, onion and cabbage, top with the kebab slices, and a generous helping of chilli sauce.