Chicken Tagine with Fennel Preserved Lemons and Green Olives

Name: Chicken Tagine with Fennel, Preserved Lemons, and Green Olives
Ingredients: For the marinade:; 1 large shallot; 3 garlic cloves; 2-inch knob ginger, peeled; 1 cup cilantro leaves, plus more for garnish; Zest of 1 lemon; Juice of 1 lemon; 1 teaspoon salt; ¼ cup olive oil; For the tagine:; 4 whole chicken legs; 1 tablespoon olive oil; 1 medium yellow onion, diced; 1 fennel bulb, trimmed, quartered, and thinly sliced; One 15-ounce can chickpeas, rinsed and drained; 1 quart chicken stock or water; 2 small preserved lemons, pith removed, and zest thinly sliced; ½ pound pitted green olives (kalamata); 2 teaspoons fresh thyme (optional)