Heat the oven to 350°.
Season chicken with salt and pepper. In a sauté pan over medium-high heat, heat 2 tbsp oil; sear chicken on all sides, remove from sauté pan and arrange in a baking pan.
In the same sauté pan, heat the remaining 3 tbsp oil and sauté onion and leeks until onions start to brown, 4 to 5 minutes; add garlic and continue to cook, 3 minutes. Season with salt and freshly ground black pepper, and deglaze the pan with wine.
Add the chicken stock, olives lemon, and bay leaves, lemon and bring to a simmer. Pour stock mixture over the chicken in the baking pan. Cover the pan and bake until chicken is cooked through, 1 hour.