Slowly heat the oil in the tagine (or Dutch oven). Gently fry the chicken until golden brown on all sides. Remove the chicken.
Add the onions, celery, red pepper and garlic to the oil. Sauté the vegetables until lightly colored.
Add the chicken legs, broth, potatoes, chickpeas, tomato puree, ginger, cinnamon, cumin and turmeric. Bring to a boil. Put the lid on and cook in the oven for 45 to 50 minutes.
Add the raisins, olives and roasted almonds. Put the lid back on and bring to a boil again. Leave to stand for 3 to 5 minutes.