Make the chermoula by putting all the ingredients in a screw-top jar and shaking to combine. Mix half the paste with the chicken and set aside.
Heat the oil in a large frying pan over a medium heat and fry the onion for about 8 minutes until soft and golden. Increase the heat a little, tip in the coated chicken and cook for about 12 minutes, stirring frequently. Stir in the chickpeas, apricots, saffron and the remaining chermoula paste and cook for a further 3–4 minutes. The chicken and spices should be cooked through.
Stir in the spinach and cook until just wilted, then add the preserved lemon (if used) and herbs. Serve immediately on warm pitta or flat breads.