Scalloped Potatoes

Why I Love This Recipe
When I was a girl, my mother made wonderful scalloped potatoes for our large family. She made this dish without making a white sauce; she would sprinkle layers of sliced potatoes with flour, salt, pepper, and butter, and pour milk over all, and it would somehow bake into creamy goodness with a crispy and crusty top. Over the years, I tried unsuccessfully to master her method - my attempts would curdle as often as not. I have used this recipe for years, and it consistently turns out well.
Ingredients You'll Need
3 Tbsp butter
2 Tbsp flour
1 1/2 tsp salt
1/4 tsp pepper
1/4 cup chopped onion
3 cups milk
6 medium potatoes
Directions
Preheat oven to 350 degrees F.
Grease a 2 quart casserole or baking pan.
Melt butter in a large saucepan.
Stir in flour, salt, and pepper. Cook and stir a few minutes.
Add milk; cook and stir until thickened and bubbly. Cook on low for about 2 more minutes.
Peel potatoes and slice thin.
Put half of the potatoes in the prepared pan. Sprinkle with salt and pepper to taste and half of the chopped onions.
Pour half of the white sauce over the potatoes.
Repeat with remaining potatoes, onion, and sauce.
Cover and bake for 45 minutes; remove cover and bake for another 30 minutes until potatoes are done.