Wash and slice yellow potatoes and boil them for about 7 to 10 minutes or until fork tender.
In a medium sauce pan melt the butter over medium heat. Then add in the flour and stir with a whisk until well blended. Then add in milk and continue stirring with a whisk until smooth and creamy.
Then stir in onion powder, garlic salt, and salt and pepper.
Lightly grease a 9 x 9 inch square baking dish. Cover bottom of pan lightly with about 1/4 cup of the sauce. Spread half of the sliced potatoes in the bottom of the pan. Top with half of the ham and half of the chicken. Pour half of the sauce and then top with about 1/2 cup of cheese. Then repeat layers starting with potatoes, ham, chicken, sauce and 1/2 cup of cheese.
Bake in 375 oven for 25 to 30 minutes until heated through. Then top with remaining 1 cup of cheese and cook for a few more minutes until cheese is melted.
Notes
If your family does not prefer Swiss cheese, you can sub for mozzarella or Provolone cheese.You can also top this with some bread crumbs and melted butter to make it more like authentic Chicken Cordon Bleu!