Preheat your oven to 350°F (175°C).
Prepare the Minute Rice according to the package instructions (microwaving works well if you're in a hurry or want to keep the kitchen cool!). Set the cooked rice aside.
In a large mixing bowl, combine the cooked shredded chicken, prepared rice, cream of chicken soup, room temperature cream cheese, Italian dressing seasoning mix, garlic powder, and chicken stock. Stir until everything is well mixed and creamy.
Fold in 1 ½ cups of the Colby Jack cheese into the mixture and mix thoroughly.
Spray a 9x13-inch baking dish with cooking spray, then pour the chicken and rice mixture evenly into the dish.
Top the casserole with the remaining ½ cup of Colby Jack cheese and 1 cup of Panko bread crumbs.
Dot the top with butter, distributing the slices evenly across the casserole.
Bake uncovered for 25-30 minutes, or until the casserole is bubbly and the top is golden brown and crispy.
Optional: Garnish with chopped parsley before serving for a fresh pop of color.