In a pot, add the whole chicken, cinnamon stick, white pepper, whole black peppercorns, cardamom pods, bay leaf, allspice, and about 8 cups of water (don't add the sumac). Bring to a boil. Boil for 60 minutes or until completely cooked through.

While the chicken boils, slice up the onions, and in another pot add them in with the olive oil and cook on medium heat until translucent for about 20 minutes. To speed up the process, add ½ teaspoon salt.

Once the chicken and onions are both fully cooked, take the chicken out of the water and shred. Add the shredded chicken to the onion pot. Add all the sumac and mix until well incorporated. Add pine nuts if using.

Fold the flatbread in half and cut down the middle so you have 2 folded halves. Place the chicken and sumac on the widest end, tuck in the sides, and roll. Do this until your mixture is all rolled up.

Preheat your oven to 350 ℉ (180 ℃). Grease the baking pan with olive oil and line up your rolls. Brush with olive oil or leftover chicken stock.

Bake until the tops are golden (about 15 to 20 minutes). Garnish with more sumac and pine nuts if using.