Start by heating the olive oil in a large tagine or Dutch oven over medium heat. Add the onion and garlic, and sauté for a few minutes until they are softened and lightly browned.
Add the chicken thighs to the pot, skin side down, and sear them for a few minutes until they are golden brown. Flip them over and sear the other side as well.
Once the chicken is seared, remove it from the pot and set it aside. Add the ginger, cumin, paprika, turmeric, corriander and cinnamon to the pot, and stir until the spices are fragrant.
Add the preserved lemon slices to the pot, and stir them into the spice mixture. Then, add the chicken broth and honey, and stir to combine.
Return the chicken to the pot, nestling it into the liquid and lemon slices. Season with salt and pepper to taste.
Cover the pot with the tagine lid or a tight-fitting lid, and reduce the heat to low. Let the chicken simmer for 45-60 minutes, or until it is cooked through and tender.
Once the chicken is cooked, remove it from the pot and set it aside. Turn up the heat to medium-high, and let the sauce simmer for a few minutes to thicken slightly.
Serve the chicken hot, garnished with chopped cilantro and a spoonful of the lemony sauce.