Microwave the potatoes for 3 minutes, stir, and microwave another 3 minutes.
In small pot, mix soup and 2 cans milk until gently boiling. Add flour and stir quickly using a whisk, then add cheese until melted. Remove from heat.
Layer half the potatoes in a 2 qt. baking dish and sprinkle with pepper. Add half the onion and ham. Repeat using remaining ingredients. Remember to pepper the 2nd layer of potatoes.
Pour the sauce over the potatoes and poke with a spoon to settle everything into place. If the sauce is not covering the top of the ingredients, add more milk.
Cover the dish and bake in oven for 1 hour. Enjoy!
Notes
I don't use salt in this dish, because ham can sometimes be salty.