Toss chicken pieces in a bowl with olive oil, garlic powder, onion powder, paprika, salt, and pepper. Let it sit for a few minutes to marinate.
Heat the grill to medium-high. If using skewers, thread the chicken with some space between each piece for even cooking.
Grill the chicken for 8-10 minutes, turning occasionally, until golden-brown and fully cooked (internal temperature should reach 165°F). For extra flavor, baste with olive oil or marinade during grilling.
Mix mayonnaise, Greek yogurt, minced garlic, lemon juice, salt, and pepper in a bowl until smooth and creamy.
Let the chicken rest for a few minutes before serving. Drizzle the creamy garlic sauce over the chicken or serve on the side for dipping. Garnish with fresh parsley.