Whisk together the ingredients for the base marinade and divide into three bowls.
Add the ingredients for each marinade into each bowl and divide the chicken pieces into each bowl. Cover and place in the fridge, preferably overnight.
For the rice base, fry the sliced onions and coriander stalks in the butter with the whole spices and a good pinch of salt for 20-30 minutes, until caramelised.
Meanwhile, add all the ingredients for the salad into a large bowl and set aside.
Add the rice to the onion base and gently coat everything in the onions and butter. Turn the heat up a bit, and when you hear the rice sizzling in the base of the pot, pour in the chicken stock and tuck all rice grains beneath the water. Taste for salt, then cover with greaseproof paper and a tight-fitting lid. Boil for 3 1/2 minutes on high, then reduce to very low and cook for a further 7 minutes. Remove from the heat and stand for 10 minutes with the lid on. Remove lid and rest for 5 minutes.
Thread the chicken, using alternate colours, onto two wide kebab skewers. If you have a charcoal grill, grill them over a medium/low heat until slightly charred and cooked through.
Place the two grilled and buttered breads next to each other and top with a large strip of rice.
Place the cooked chicken on top and the salad on the side, then pour tahini sauce down the other side.
Top with your favourite kebab accoutrements - herbs, pomegranate seeds, red onion pieces.