• Whisk ¼ cup of oil, lemon juice, garlic, salt, Sumac, Baharat, and black pepper in a bowl. Add Chicken to a Ziploc bag and pour the marinade over the chicken. Place the bag in a bowl (to avoid leakage) and allow the chicken to marinate in the fridge for 2 or more hours).
• Toast the pine nuts in a hot pan. Agitate the pan over low heat until the pine nuts are toasted and lightly browned.
• Preheat oven to 400 degrees F.

  Heat 2 tablespoons oil in a large pan then sear the chicken on both sides before adding it to a baking dish. Bake the chicken for 20 to 25 minutes or until the chicken is cooked all the way through. Boneless chicken will require less time.
• Add chopped onion to the same pan and saute over low to medium heat until the onions are caramelized. This should take approximately 20 minutes, don't rush it. During the last few minutes, add the remaining Baharat, Sumac Powder, and salt. 
• When there are 5 minutes remaining for the chicken to be done, brush the tops of the flatbread with some of the pan juices, then place the flatbread directly on the racks in the oven to get toasty.

Assembly

• To assemble the Musakhan, distribute the caramelized onions and pine nuts over the flatbread. Top each with a piece of chicken, and sprinkle with additional toasted pine nuts, sumac onions, and Sumac Powder.