Preheat your oven to 375°F (190°C).
In a large skillet, melt 2 tablespoons of butter over medium heat. Add the minced garlic and sauté for about 1 minute until fragrant.
Add the chicken pieces to the skillet, season with salt, pepper, onion powder, garlic powder, and Italian seasoning. Cook for about 5-7 minutes, stirring occasionally, until the chicken is cooked through.
In a large mixing bowl, combine the cooked rice, chicken mixture, chicken broth, heavy cream, frozen peas and carrots, and the remaining 2 tablespoons of butter. Stir until well combined.
Transfer the mixture to a greased 9x13 inch baking dish. Spread it evenly and top with shredded cheddar cheese.
Cover the dish with aluminum foil and bake in the preheated oven for 20 minutes.
Remove the foil and bake for an additional 10 minutes, or until the cheese is bubbly and golden.
Let the casserole cool for a few minutes before serving.