Preheat oven to 350℉ and grease a 9×13-inch baking dish
In a large bowl (or right in the baking dish), whisk together the cream of chicken soup and milk
Add the sliced potatoes, ham and 1 cup of the shredded cheddar cheese and stir until the potatoes are all coated
Spread to an even layer in the greased pan
Cover with foil and bake for 1 hour
Remove the foil and stir the potatoes. Top with the remaining cheese
Bake an additional 30 minutes uncovered, or until the potatoes are tender and the edges of the pan are bubbly
Let set for 5 minutes and serve warm
