A steaming dish of these on a cold day will make your tummy cozy! I LOVE scalloped potatoes-- these are sooooo creamy. I love them as a side dish, and I've made this into a one-dish casserole when I want it for dinner. Note: I usually double this recipe, as it goes quickly with my kids! If you double the recipe, too, add a can of cream of chicken or cheddar cheese soup to help thicken.
Preheat oven to 350. Wash potatoes but don't slice them until ready to bake.
Melt butter & get that nice & bubbly & golden. Then, add flour to make a roux. Once nice & bubbly, slowly add milk. Add about a tablespoon of salt. (Note: I like to add some peppercorns to this, but you can just add some ground black pepper instead). Cook over medium heat, stirring constantly, about 20 minutes. Add the mustard (you may use ground, if you prefer). Whisk (or stir) well. This will be your "sauce" for the potatoes. If you desire, add a can of cream soup now.
While cooking milk mix, saute ham cubes & onion diced in about 1 tablespoon of butter. Drain well.
Slice potatoes & lay in casserole or baking pan. Mix in ham & onions, then pour your sauce over top.
Stir to mix well. Bake for one hour with lid on; 30 mins with lid off. If adding cheese, I add the last 15 minutes on top to melt. Sprinkle w/ paprika & let sit about 10 mins before digging in. YUMMY!