Make the sauce. Add the chicken soup, evaporated milk, cream cheese and ranch mix to a saucepan. Place over medium heat. Whisk until the sauce is smooth and combined.
Add a ladle of sauce on the bottom of the casserole dish.
Place a layer of sliced potatoes then a layer of cubed ham. Add ⅓ of the remaining sauce.
Repeat layers. Finishing with cheesy sauce. Top with shredded mozzarella and cheddar cheese. Cover with foil.
Place in the oven on the middle rack. Bake for an hour and half covered.
Uncover, place under broiler for 3-5 minutes until it's golden brown. Watch it carefully so it doesn't burn. You're just looking to brown the cheese!
Allow to sit at least 15 -30 minutes lightly covered with foil after you remove it from the oven.
Cubed salty ham adds a meaty flavor to this casserole dish but you could also use shredded or cubed chicken or turkey instead. For an extra cheesy texture to this recipe, consider sprinkling an additional layer of shredded cheese with the repeated layers of potato, ham and creamy sauce.While I’ve sliced my potatoes for this casserole (as you would for au gratin potatoes), you can cut them into cubes if you’d prefer. It won’t alter the taste, just look a little different!Don't skip browning the top of the casserole - the browned cheese is absolutely amazing!