Prep Time: 10 minutes
Cook Time: 30 minutes
Total Time: 40 minutes
Servings: 6
Preheat oven to 400°F.
Heat an oven-proof pot over medium heat and melt butter.
Add onions and garlic and cook until fragrant, about 2 minutes.
Sprinkle in flour and cook until slightly golden, 2 minutes more.
Pour in chicken broth and heavy cream and bring to a boil.
Season with salt, pepper, and mustard powder.
Reduce heat to medium-low and simmer until liquid coats the back of a spoon, 10-12 minutes.
Stir in cooked pasta, chicken, ham, and swiss cheese.
Sprinkle top with Parmesan.
Bake until warmed through, 10-12 minutes.
For a golden top, broil for an extra 2-3 minutes.
Garnish with parsley.