Preheat oven to 375 degrees Fahrenheit and grease a 9x13 inch baking dish.
Arrange the raw chicken pieces in an even layer at the bottom of the prepared dish.
Distribute the chopped ham evenly over the chicken.
Layer the shredded Swiss cheese over the ham.
In a bowl, whisk together the cream of chicken soup, milk, Dijon mustard, garlic powder, onion powder, and black pepper.
Pour the sauce mixture over the ingredients in the baking dish.
In a separate bowl, mix Panko breadcrumbs with melted butter until coated.
Sprinkle the breadcrumb mixture uniformly over the casserole.
Bake for 35 to 40 minutes until the chicken reaches an internal temperature of 165 degrees Fahrenheit.
Garnish with fresh parsley and allow to rest for 5 minutes before serving.