1. Mix all the marinade ingredients in a bowl and add the chicken thighs place in fridge for 2 -12 hours (the longer the better). Marinade ingredients olive oil, garlic, lemon juice, salt, pepper, paprika, cumin, turmeric, allspice, cinnamon and red pepper flakes.
2. Pull chicken out of fridge 30 minutes prior to baking. Mix red onion in with the chicken and marinade place the chicken and red onion in a baking sheet pan. Bake chicken for 30 minutes at 425 degrees until cooked through.
3. After baking let chicken rest for 5 minutes and then cut into fajita style slices.
4. Place olive oil (1-2 tablespoons) in frying pan on medium high heat and fry chicken slices till crispy for around 2 to 3 minutes work in batches. Oil should be very hot before adding chicken.
5. Chicken shawarma is served with tomatoes, cucumbers and a tahini sauce drizzle over the top. You can also wrap up your chicken shawarma in pita or lavash wrap.