Preheat the oven: Set the oven temperature to 175°C (350°F). Grease a 9 x 13-inch baking dish with non-stick spray or butter.
Cook the pasta: Boil egg noodles (or your chosen pasta) until al dente, about 6-8 minutes. After draining, set aside.
Mix the creamy base: In a large bowl, whisk together cream of chicken soup, sour cream, milk, Dijon mustard, garlic powder, onion powder, salt, and pepper until smooth.
Combine the main ingredients: Add the cooked pasta, shredded chicken, diced ham, and 1.5 cups of Swiss cheese to the creamy mixture. Stir until the coating is uniform.
Assemble the casserole: Evenly distribute the mixture in the baking dish that has been prepared. Add the remaining 1/2 cup of Swiss cheese on top.
Add the topping (optional): If using breadcrumbs, mix panko with melted butter and sprinkle over the casserole for a crispy finish.
Bake: Place the casserole in the oven and bake for 25-30 minutes until the cheese is bubbly and the top is golden brown.
Garnish and serve: Before serving, take it out of the oven, sprinkle it with fresh parsley, and let it rest for five minutes.