Preheat your oven to 375°F (190°C).

In a large skillet, heat the olive oil over medium heat. Add the diced chicken and season with garlic powder, onion powder, oregano, salt, and pepper. Cook until the chicken is browned and cooked through, about 6-8 minutes.

In a mixing bowl, combine the Greek yogurt, lemon juice, and grated cucumber. Stir until well mixed.

In a large baking dish, combine the cooked rice, cooked chicken, and half of the tzatziki mixture. Mix well to combine.

Spread the remaining tzatziki mixture over the top of the rice and chicken mixture.

Scatter the halved cherry tomatoes and shredded mozzarella cheese evenly on top.

Bake in the preheated oven for 25-30 minutes, or until the cheese is melted and bubbly.

Remove from the oven and let it cool for a few minutes. Garnish with chopped parsley before serving.