In a large bowl, season the chicken with 3 Tbsp each za'atar and olive oil, 1 Tbsp sumac and a pinch of salt. Mix well to combine. Set aside while you prep the other ingredients.
Heat a large pan with 2 Tbsp oil, add the chicken and green chillies. Cook, stirring often, on medium heat for 5-7 minutes or until the chicken is almost cooked through. Remove from pan and set aside, leaving any oil in the pan.
Add 1 Tbsp oil to the pan. Add the onions and cook for 5-7 minutes until the onions soften. If the onions start to burn on the bottom before turning brown, add a splash of water to prevent it from burning.
Stir in 1/4 cup raisins and 1 1/2 cups pearl couscous. Mix and cook for a few minutes so the pearl couscous starts to toast and turn a bit golden.
Add 1 3/4 cup broth and mix well. Bring to a boil, turn the heat down, cover and simmer for 10-15 minutes until the liquid is mostly absorbed.
Once the liquid is mostly absorbed, remove the lid from the pan and add the chicken back into the pan on top of the couscous. Cover and let it cook for another 5 minutes.
Meanwhile, in a small bowl mix the remaining 2 Tbsp za'atar in 2 Tbsp olive oil and mix well. Set aside.
Just before serving, drizzle with the za'atar olive oil, sprinkle with dried pomegranate powder, fresh pomegranate seeds and fresh cilantro. Enjoy!