To prepare the chicken shawarma marinade, combine the lemon juice, olive oil, garlic, paprika, cumin, pepper, salt, turmeric, and red pepper flakes in a small blender or bowl and mix until well combined.
Add the chicken thighs to a shallow bowl, tray or resealable freezer bag and pour in the marinade. Toss until the chicken is well coated. Store in refrigerator for at least 1 hour or up to 12 hours.
When ready to cook, preheat oven to 425 degrees. Brush a tablespoon of oil evenly across a rimmed baking sheet. Remove the chicken thighs from the marinade and place evenly spaced out on the greased pan.
Place in the oven and roast for 25-30 minutes or until the chicken is cooked through and browned and crispy around the edges. You may wish to broil it for the last 2-3 minutes to get it extra browned and crispy.
Remove from the oven and allow it to rest for 2 minutes. Using a sharp knife, cut chicken into slices or small pieces.
Divide chicken among pitas along with hummus and/or tzatziki, tomatoes, lettuce, red onion, feta or other desired toppings. Finish with a sprinkle of parsley, fold up the wrap and serve.