Place the saffron in a small bowl, cover with 2 tablespoons of hot water and leave to soak for a few minutes.
Cut the chicken into 4cm cubes and place in a bowl with the yoghurt, saffron and soaking liquid. Peel and finely grate in the garlic clove and the zest from both lemons, then squeeze in the juice from one. Drizzle with extra virgin olive oil and season lightly with sea salt and freshly ground black pepper, then mix together and leave to marinate in the fridge for at least 1 hour, but preferably overnight.
Preheat the oven to 180°C/350°F/gas 4. Peel and finely slice the red onions, quarter the tomatoes and pick the coriander leaves. Place everything into a bowl, keeping a few coriander leaves back to use later as a garnish. Squeeze in the juice from the remaining lemon, add a small pinch of salt and scrunch together really well. Add a good lug of extra virgin olive oil, correct the seasoning and set aside.
Preheat a griddle pan to high. Thread the marinated chicken pieces onto 4 skewers – if you're using wooden ones, make sure you soak them in water first to stop them burning and also cut them to size, if necessary.
Griddle the chicken kebabs for around 10 minutes, or until golden and cooked through, turning regularly.
Meanwhile, pop your flatbreads in the oven to warm through.
To serve, place the flatbreads onto 4 plates and pop a skewer on top of each one. Divide the tomato salad and all the lovely juices between the flatbreads, drizzle lightly with extra virgin olive oil and scatter over the reserved coriander, then serve right away.