Preheat the Oven: Set the oven to a temperature of 450 degrees Fahrenheit to ensure it is adequately heated for baking.
Cook the Broccoli: Place the chopped broccoli in a saucepan, cover with water, and bring to a boil over high heat. Allow the broccoli to cook for approximately 5 minutes or until it becomes tender. Afterward, remove from heat, drain well, and set aside.
Assemble in Baking Dish: Arrange the drained broccoli at the bottom of a 9-inch pie plate. Evenly distribute the sliced chicken over the broccoli, creating an even layer.
Prepare the Cream Sauce: In a mixing bowl, combine the condensed cream of broccoli soup with the milk. Whisk together until the mixture is smooth. Gently pour this mixture over the chicken, ensuring it evenly covers the surface.
Add Cheese and Breadcrumb Topping: Sprinkle the shredded cheddar cheese over the sauce-covered chicken. In a separate small bowl, mix the melted butter with the dried bread crumbs until the mixture achieves a sandy texture. Evenly distribute this breadcrumb mixture across the top of the cheese.
Bake the Dish: Place the assembled dish in the preheated oven and bake for 15 minutes, or until the topping turns golden brown and the dish is bubbling throughout.
Serving: Remove from the oven, allow to cool slightly, and serve while warm. Enjoy the rich flavors and comforting textures of this classic dish.