In a large mixing bowl, combine olive oil, cumin, coriander, paprika, turmeric, cinnamon, allspice, garlic powder, onion powder, black pepper, and salt.

Add the lemon juice, minced garlic, white vinegar, and yogurt. Mix well to create the marinade.

Add the chicken thighs to the marinade and coat them thoroughly.

Cover the bowl and refrigerate for at least 1 hour, or preferably overnight, to allow the flavors to infuse.

In a small bowl, whisk together Greek yogurt, minced garlic, lemon juice, olive oil, tahini (if using), salt, and pepper. Mix until smooth and creamy.

Set aside the sauce.

Preheat a grill pan or skillet over medium-high heat.

Once hot, add the marinated chicken thighs and cook for about 6-8 minutes per side, or until the chicken is fully cooked through and has an internal temperature of 165°F (75°C).

Remove the chicken from the heat and let it rest for a few minutes.

Slice the chicken into thin strips.

Warm the pita bread or flatbread.

Layer the sliced chicken on the bread, then add sliced tomatoes, cucumbers, and fresh parsley.

Drizzle with the creamy garlic sauce and serve immediately.

For extra char, finish under a broiler for 1-2 minutes, watching closely.