Combine the paprika, black pepper, cinnamon, cumin, ginger, and salt in a small bowl.

Mix 1 tablespoon of the spice mixture with the flour in a shallow dish. Coat the chicken pieces evenly in the seasoned flour, shaking off any excess. Reserve the remaining spice mixture.

Heat the olive oil in a large Dutch oven over medium-high heat. Add the chicken and cook for about 7 minutes, turning occasionally, until browned on both sides. Transfer the chicken to a plate.

Add the onions, carrots, garlic, and reserved spices to the same pot. Cook for about 5 minutes, stirring frequently, until the onions soften and begin to brown.

Return the chicken to the pot. Add the potatoes, olives, preserved lemon, 2 tablespoons each of cilantro and parsley, bay leaves, and chicken stock.

Bring everything to a gentle boil. Reduce the heat to low, cover, and simmer for about 1 hour, or until the chicken is fully cooked and tender and the potatoes are soft. This slow simmer gives the Chicken Tagine with Preserved Lemon its rich, aromatic flavor.

Remove the bay leaves. Sprinkle with the remaining cilantro and parsley, then serve warm with cooked couscous if desired.