In a large bowl, combine plain Greek yogurt, olive oil, lemon juice, ground cumin, smoked paprika, ground coriander, garlic powder, salt, and black pepper. Mix until smooth and all spices are blended.

Add the chicken thighs to the marinade, coating thoroughly. Cover and refrigerate for at least 1 hour, preferably overnight.

Preheat your oven to 425°F (220°C) or heat your grill to medium-high.

Prepare your cooking utensils, lining a baking sheet with parchment paper or greasing the grill grates lightly with olive oil.

Place the marinated chicken thighs on the prepared baking sheet or grill. Bake for 25–30 minutes or grill for 5–6 minutes per side until juices run clear and the internal temperature is 165°F (75°C).

Let the cooked chicken rest for about 5 minutes, then slice thinly against the grain.

Serve your Shawarma Chicken with warm pita, Greek salad, or drizzled with tahini sauce.