Set your oven to 375°F (190°C). Lightly grease your baking dish to prevent sticking. Preheating ensures even cooking and a tender casserole.
Mix uncooked rice, chicken broth, olive oil, garlic, dill, oregano, cumin, salt, and pepper in the baking dish. Spread the rice evenly for uniform cooking.
Arrange chicken pieces over the rice. Whisk yogurt, grated cucumber, and lemon juice, then pour over chicken and rice. Spread gently to coat everything.
Cover with foil and bake for 35-40 minutes until rice is tender and chicken reaches 165°F. Moisture from foil keeps chicken juicy and rice fluffy.
Sprinkle feta (if using) and return to oven for 5 minutes uncovered. Garnish with parsley or cilantro for fresh flavor and visual appeal.
Let the casserole rest 5 minutes. Serve warm with a Greek salad, cucumber salad, or pita for a complete Mediterranean meal.