In a large pot, add all the diced onions. Cover and cook while sporadically stirring as to not burn the bottom on medium heat. The onions will start to soften.
In the meantime, use the ingrdients in the chicken prep to clean the chicken's that should be halved. Let them soak in this for 10 minutes or so before rinsing off and patting dry.
Now, mix all the ingreidents for the chicken marinade until it looks sauce like. Add all the chicken pieces to a lightly oiling baking pan. Then, completely coat with this chicken marinade. *You can either add the sumac as a spirnkle on each chicken at the end or in the actual sauce.
Cover the chicken and bake in a 420 F oven for 1.5 hours. Chicken is cooked once it reaches an internal temperature of 165 F.
Back to the onions! At this point, the onions should be very soft and translucent. Now add the salt, cumin, and olive oil. Let this simmer together for about 10 minutes then drain the olive oil from the onions and set aside.
Take out the thick flatbread you will be using for the dish. If you have access to taboon bread that would be perfect for this. First, oil the bread evenly with the drained oil. Then, top with the cooked onions evenly. Then, sprinkle with sumac all over the top of each flatbread. Repeat with the other flatbreads.
Broil the flatbreads in the oven for about 2 minutes until they are lightly crisped.
To assemble, top the flatberads with the cooked chicken, a garnish of parsley, and toasted almonds. Enjoy with plain yogurt and arabic salad.