01 - In a large bowl, combine olive oil, minced garlic, paprika, cumin, oregano, coriander, chili powder, lemon juice, salt, and black pepper. Add the chicken and toss thoroughly to coat evenly. Cover and marinate for at least 15 minutes at room temperature or up to 2 hours refrigerated.
02 - Heat a grill pan or skillet over medium-high heat. Cook the marinated chicken for 6 to 7 minutes per side until fully cooked through with a golden char. Transfer to a cutting board and rest for 5 minutes before slicing thinly against the grain.
03 - While the chicken rests, whisk together Greek yogurt, tahini if using, lemon juice, finely grated garlic, salt, and pepper in a small bowl until smooth. Adjust seasoning to taste.
04 - Warm the pita breads and arrange on plates. Fill each pita with a layer of shredded lettuce, sliced chicken, halved cherry tomatoes, diced cucumber, red onion, and chopped parsley. Drizzle generously with the yogurt sauce.
05 - Serve immediately while warm. Pair with a crisp white wine or sparkling water with lemon for a refreshing accompaniment.