To begin, in a large bowl, combine the grated onion, minced garlic, ground ginger, turmeric, cumin, paprika, cinnamon, saffron, olive oil, salt, and black pepper. Mix thoroughly to create a smooth marinade. Add the chicken pieces, ensuring each one is well coated. Cover and let marinate for at least 1 hour or overnight in the refrigerator for a deeper flavour.

In a tagine or a large heavy-bottomed skillet, heat 2 tablespoons of olive oil over medium heat. Add the sliced onion and sauté for 5-6 minutes until softened and golden, forming the aromatic base of the stew.

Add the marinated chicken pieces to the tagine, arranging them in a single layer. Pour the remaining marinade over the chicken. Cook the chicken for 5-6 minutes on each side, allowing it to brown lightly. This step enhances the flavour of the dish.

Add the preserved lemon quarters and olives to the tagine, tucking them between the chicken pieces. This adds both a tangy and salty note, which is characteristic of traditional Moroccan tagines.

Pour the chicken broth or water into the tagine, ensuring that the liquid reaches about halfway up the chicken pieces. This will help keep the chicken moist while cooking. Bring the mixture to a gentle simmer.

Reduce the heat to low, cover the tagine with its lid, and let it simmer gently for 45 minutes to 1 hour. Check occasionally to ensure the liquid has not evaporated too much, if needed, add a little more broth or water.

Towards the end of cooking, add the chopped cilantro and parsley to the tagine, reserving some for garnish. Stir gently to combine, allowing the herbs to infuse their fresh flavours into the dish for the final 10 minutes of cooking.

Serve the chicken tagine directly from the tagine vessel for an authentic presentation. Garnish with the reserved herbs and serve alongside warm couscous or fresh Moroccan bread for soaking up the flavourful sauce. Consider adding a few extra wedges of preserved lemon for those who enjoy a more pronounced citrus note.