Scalloped Potatoes with Ham

adapted from Betty Crocker's New Cookbook

6 medium baking or boiling potatoes (about 2 pounds)
4 tablespoons butter (or margarine)
1 small onion, finely chopped
3 tablespoons all-purpose flour
1 teaspoon salt
1/4 teaspoon freshly ground black pepper
3 cups milk
Leftover ham- sliced or diced

1. Heat oven to 350ºF. Spray the bottom and sides of a 9x13 baking dish with cooking spray.

2. Wash and peel potatoes if desired (you could leave the peels on). Cut into thin slices (Or use a food processor/mandolin) until you have 4 cups of potato slices.

3. Place potato slices in baking dish, add ham as desired, and mix together with your hands, layering the potatoes and ham however you would like.

4. In a saucepan over medium heat, melt butter. Cook onion in butter about two minutes, or until softened. Add flour, salt and pepper, whisking constantly. Cook and stir until smooth.

5. Gradually, pour milk into flour mixture, stirring to combine completely. Heat to boiling, stirring constantly. Once it's boiling, cook and stir for about one minute.

6. Pour sauce over prepared potatoes and ham.

7. Cover with foil and bake for 30 minutes. Remove foil and bake for 1 hour or a little longer until the potatoes are tender. (depends on the thickness of the slices) Let stand 5 to 10 minutes before serving.