Grease a 9 x 13-inch baking dish or spray it with nonstick cooking spray.
In the prepared dish, combine the chicken with lemon juice, olive oil, parsley, oregano, thyme, smoked paprika, seasoned salt, cumin, onion powder, garlic powder, black pepper, turmeric, and cayenne. Let the chicken marinate in the herbs and spices at room temperature for 30 minutes while the oven preheats. Preheat the oven to 375°F (190°C).
Add the uncooked rice, grated zucchini, and chicken broth to the pan with the chicken. Stir everything together.
Cover the dish tightly with foil and bake for 40 minutes, or until most of the liquid is absorbed and the rice is tender. If the rice is still firm after 40 minutes, cover the dish again and return it to the oven for an additional 5-10 minutes, or until the rice is fully cooked. The total cooking time may vary depending on factors like the type of baking dish you use and your oven. For example, glass or ceramic dishes may take longer than metal pans. To check if the casserole is done, taste a bite of the rice. It should be tender, and most of the liquid should be absorbed. Fluff the rice with a fork, taste, and season with additional salt and pepper if desired. Serve the chicken and rice topped with tzatziki, fresh herbs, and lemon.