Preheat your oven to 375°F (190°C). Cook diced chicken in a large skillet over medium heat until golden brown, about 6-8 minutes. Prepare rice according to package instructions and set aside.

In the same skillet, add olive oil and sauté chopped onions and minced garlic for about 3-4 minutes until fragrant. Stir in chopped vegetables and cook for another 5-7 minutes until tender.

In a large mixing bowl, combine cooked chicken, rice, and sautéed vegetables. Pour in vegetable broth and your favorite seasonings, mixing everything thoroughly.

Grease a 9x13-inch casserole dish, transfer the mixture, and spread it out evenly. Top with shredded cheese if desired.

Bake for 25-30 minutes, or until the top is bubbly and golden brown. Cover lightly with foil if it browns too quickly.

Allow the casserole to cool for about 5-10 minutes before serving to help the flavors meld.