In a large bowl, mix yogurt, olive oil, garlic, lemon juice, and all spices.
Add chicken and coat well. Marinate at least 1 hour or overnight.
In a separate bowl, whisk mayonnaise, Greek yogurt, garlic, lemon juice, olive oil, and salt to make garlic sauce. Chill until serving.
Heat a skillet or grill over medium-high heat.
Cook chicken for 5–7 minutes per side until charred and fully cooked (165°F internal temperature).
Let chicken rest for a few minutes, then slice thinly.
Serve with garlic sauce in pita wraps, shawarma bowls, or over rice.