In a large bowl, mix the yogurt, minced garlic, lemon juice, olive oil, 7-spice, paprika, salt, and black pepper.
Toss the meat pieces thoroughly in the marinade and place in the refrigerator. Marinate for a minimum of 2 hours, ideally 8-12 hours.
The key to Zarb's success is long, slow cooking at a low temperature, which allows the food to 'stew' in its own juices and steam. This ensures the meat is incredibly tender and the vegetables absorb the rich flavor of the meat and marinade.
Bedouins traditionally use lamb or goat meat, but chicken is equally excellent and requires less baking time. The marinade with yogurt and 7-spices is essential.
In a large bowl, mix the yogurt, minced garlic, lemon juice, olive oil, 7-spice, paprika, salt, and black pepper.
Toss the meat pieces thoroughly in the marinade and place in the refrigerator. Marinate for a minimum of 2 hours, ideally 8-12 hours.
In a separate bowl, toss the chopped potatoes, carrots, and onion with olive oil, salt, and Za'atar (or oregano).
In a deep roasting pan (or Dutch oven), layer the vegetables first and place the marinated meat on top.
Tightly cover the pan with a lid, and then wrap the entire container with 2-3 layers of heavy-duty aluminum foil. The goal is to prevent any steam from escaping, creating an 'underground effect'.
Preheat the oven to a low temperature of 150 °C (300 °F). Bake covered for 3.5 hours. If using only chicken, 2.5 hours will suffice.
After 3.5 hours, carefully remove the aluminum foil (watch out for hot steam). Increase the oven temperature to 200 °C (392 °F).
Bake uncovered for another 15 minutes until the meat develops a nice brown crust.
Serve the meat and vegetables on a large platter (like Mansaf) with rice and fresh Arabic bread, optionally with a yogurt dip or s'chug sauce.