Start by making the marinade. Dry-fry the spices over a high heat until aromatic, then tip into a bowl and allow to cool. Add the remaining marinade ingredients and mix together.
Use kitchen paper to pat the chicken thighs dry all over and then add to the bowl of marinade (or tip everything into a large ziplock bag). Use your hands to massage the spices into the thighs. Leave to marinate for at least 3 hours, or overnight.
Combine all the tahini sauce ingredients in a small bowl with 2 tablespoons of water, adding a little more water to thin if needed. Cover and chill in the fridge (up to 3 days in advance) until ready to serve.
Pre-heat the oven to 200°C/180°C fan. Place a large ovenproof frying pan or griddle pan over a high heat and add the olive oil. When hot, add the chicken pieces and cook until charred on the outside (you may need to do this in batches). Return all the chicken back to the pan and transfer to the oven for 6-8 minutes until cooked through.
Remove the chicken from the oven, wrap it in foil and allow it to rest for 5 minutes, before thinly slicing the chicken with a sharp knife. Drizzle any juices remaining in the pan over the meat.
Sprinkle the flatbreads with water and pop them in the oven for 3-5 minutes to warm up. Meanwhile, combine the rocket and herbs in a bowl.
Put everything on the table so people can help themselves. Spread tahini sauce onto a flatbread, then top with chicken, rocket and herbs, sliced red onion and a sprinkle of pomegranate seeds.