In a large frying pan, heat 4 tablespoons of ghee and saute the onions on medium heat for about 10 minutes before adding the lamb and turmeric. Continue to saute for another 5 minutes. The lamb and onions should have turned a beautiful golden color and become aromatic.
Add water, cover and cook for 60 minutes on low heat or until the meat is fully cooked and tender.
In the meantime, heat the remaining 2 tablespoons of ghee and saute the spinach over medium-high heat for about 10 minutes until the spinach has fully wilted and most of the liquid has evaporated.
Once the meat has been cooked, add the salt, pepper, Aloo Zard and Ab Ghooreh and increase the temperature a bit so to remove most (but not all) of the remaining liquid. This is a dry(er) stew and should not be watery.
Add the previously sauteed spinach to the meat mixture, lower the flame, cover and cook for another 10 minutes.
Serve the Khoresh with Persian steamed basmati rice with a side of yogurt.