In a large bowl, whisk together olive oil, garlic, lemon juice, parsley, oregano, cumin, coriander, paprika, salt, and black pepper.
Add the chicken and toss until fully coated. Marinate for at least 30 minutes or up to overnight.
Preheat oven to 400°F.
Add potatoes to a 9×13 baking dish and toss with oil and seasonings. Cover and bake potatoes for 15 minutes first.
Then add marinated chicken on top, pour over remaining marinade, cover again and bake for 35–40 minutes.
Remove foil and bake uncovered for another 15–20 minutes until chicken reaches temperature and potatoes are tender.
Optional: Broil for 2–3 minutes for extra golden color and crispy edges. Top with crumbled feta, fresh parsley, and a squeeze of lemon juice before serving. Serve warm with tzatziki if desired.