Preheat your oven to 375°F (190°C). Grease a 9x13-inch baking dish.
In a large bowl, stir together the cream of chicken soup, sour cream, Dijon mustard, garlic powder, and pepper.
Add the shredded chicken and ham to the bowl. Stir to coat everything in that creamy goodness.
Transfer the mixture into your prepared casserole dish and spread it out evenly.
Sprinkle the shredded Swiss cheese over the top. Be generous—this is the cheesy crown.
In a small bowl, mix the crushed crackers with the melted butter. Sprinkle this over the cheese layer.
Bake uncovered for 25 minutes, or until bubbling and golden on top.
Let it rest for a few minutes before serving. Sprinkle with chopped parsley if you’re feeling fancy.