Preheat the oven
Preheat your oven to 350°F. Lightly grease a 9x13-inch baking dish with nonstick spray or butter.
Prepare the rice
Cook the Minute Rice according to the package directions. Once cooked, fluff it with a fork and set it aside.
The rice should be fully prepared before it goes into the casserole.
Mix the creamy filling
In a large mixing bowl, add the shredded chicken, prepared rice, cream of chicken soup, softened cream cheese, Italian dressing mix, garlic powder, chicken stock, and black pepper.
Stir until the mixture looks creamy and evenly combined.
Add the cheese
Fold in 1 1/2 cups of shredded Colby Jack cheese. Mix just until the cheese is spread throughout the chicken and rice filling.
Assemble the casserole
Spoon the creamy chicken rice mixture into the prepared baking dish. Spread it into an even layer so it bakes consistently.
Add the topping
Sprinkle the remaining 1/2 cup of Colby Jack cheese over the top.
Add the panko breadcrumbs in an even layer, then scatter the butter pieces across the surface. The butter helps the topping bake up golden and crisp.
Bake until bubbly
Bake uncovered for 25 to 30 minutes, or until the casserole is hot, creamy, bubbling around the edges, and lightly golden on top.
Rest and serve
Let the casserole rest for about 5 minutes before serving. Sprinkle with chopped parsley if you want a fresh finish.