Combine all ingredients except for chicken, fillings, and sauce ingredients to make marinade. If it seems a little dry, add a little olive oil (a tablespoon at a time).
Add chicken, cover and refrigerate at least 8 hours, preferable overnight.
In a stockpot or large saucepan, cook chicken over medium heat for 45 minutes or until done. Be sure not to overcook! If chicken becomes a little dry, add a few tablespoons of water throughout cooking duration.
While chicken is cooking, prepare the sauce. Combine sauce ingredients and mix well. Set aside.
Take the onions, tomatoes, cucumbers and sprinkle with sumac. Add any other filling ingredients in a large bowl and combine well.
When the chicken is done, you can shred it, slice it, or leave into large pieces. Just make sure it is thinly cut.
Spread each half pita with hummus.
Place enough chicken on pita that cover 1/4 of the loaf.
Add veggies and pour on sauce.
Roll like a soft taco or burrito and you have shawarma!
You can also stuff the pocket of the pita if you prefer. I prefer to roll large pitas and stuff the smaller ones.
****Cooking time does not include refrigerating overnight****.