How to Make It
In a large casserole, heat 1 tablespoon of the olive oil. Add half of the chicken, season with salt and pepper and brown over moderately high heat, about 3 minutes per side. Sprinkle half of the turmeric over the chicken, stir well and transfer the chicken to a plate. Repeat with the remaining chicken and turmeric, using the oil already in the casserole.
Add the remaining 1 tablespoon of olive oil to the casserole and stir in the onions, olives, ginger, garlic, cilantro, preserved lemon, lemon zest, chile and cumin. Cook, stirring, until the onions soften slightly, about 3 minutes.
Return the chicken to the casserole, add the water and bring to a boil. Cover partially and simmer over low heat for 1 hour. Remove the chicken parts and simmer the sauce over moderately low heat until reduced to 2 cups, about 50 minutes. Remove and discard the chile. Refrigerate the jus for 3 hours and up to 2 days. Spoon off any fat before using.