If you have a box of scalloped potatoes in your pantry, you NEED to make this easy creamy potato chicken casserole!
Preheat the oven according to the scalloped potato directions on the box.
In a large mixing bowl, combine cooked chicken, onions, garlic, broccoli, cream of chicken soup, and shredded cheese. Mix well to combine all the ingredients evenly. Set aside.
Assemble casserole. Place your scalloped potatoes in a greased casserole dish and sprinkle the contents from the cheese packet, boiling water, warmed-up milk, and butter. Mix until combined. Transfer the chicken-broccoli mixture over the potato mixture and mix, spreading everything out evenly.
Bake according to the instructions on your scalloped potato package. Make sure to have the amount of water listed on the box. Cut the casserole with a knife to ensure the potatoes are tender before removing them from the oven.
Serve while still warm.