Finely chop the onion and garlic.
Chop the carrots, celery and red pepper into small pieces.
Heat a little olive oil in a large casserole dish over a medium-low heat.
Add the chopped vegetables and gently sauté for about 8 minutes, stirring occasionally, until they begin to soften.
Add the Moroccan herb mixture, cumin, paprika, chilli flakes and ground peppercorns.
Stir for about 1 minute, until fragrant, then add the chopped tomatoes, stock cube and enough water to create a good stew-like consistency.
Bring to the boil, then cover and reduce the heat and simmer for about 20 minutes.
Add the chopped chicken, chickpeas, preserved lemon, if using, and your chosen greens.
Bring back to the boil, then cover and cook for about 10 minutes, or until the chicken and vegetables are tender and cooked through.
Stir in the olives and chopped parsley, then serve hot with couscous, rice or bulgur