put sliced potatoes, sliced ham, ^ cheddar cheese in a large mixing bowl & toss. Sprinkle flour, salt, pepper, & garlic salt over the mixture, one cup at a time - tossing & mixing well. Keep doing this until EVERY potato & ham slice have a thin coating of the flour/seasoning mixtures.
Spray the crockpot with pam to cut down on the sticking. Put the mixture into the crockpot & pour milk over all until the milk sits about 1" above the potato mixture. Reach in & toss this well to be sure every slice is coated with milk & there are no pockets with flour sitting uncoated.
Bake on high about 1 hour, then reduce heat to low & bake 3-4 hours more. It turns out best if you can continue to stir every hour or so.
You can make this recipe smaller or larger depending on who you're feeding. The only rule is to use enough flour to coat potatoes, cheese, and ham well and to drench the mixture with milk before cooking!