Scalloped Potatoes and Ham

3 small potatoes, thinly sliced
1/4 teaspoon cream of tartar
1/2 cup water
1 small onion, thinly sliced
1/2 cup diced ham
1/3 cup grated Cheddar or American cheese
Salt and pepper to taste
1/4 cup nonfat dry milk powder plus water to make 2/3 cup
2 tablespoons flour

Toss potatoes in cream of tartar and water. Drain.

Layer half the potatoes, onion slices, ham and cheese in crockette. Season with salt and pepper. Repeat with remaining half.

Mix milk with flour and pour over all. Cover and cook for 8 to 12 hours.