4 Russet potatoes, sliced into 1/4 inch slices
1 onion, sliced into rings salt and pepper to taste.
3 tablespoons butter
3 tablespoons all-purpose flour
1/2 teaspoon salt
2 cups milk
11/2 cups shredded cheddar cheese
Preheat oven to 400 F°
Butter a 1 quart casserole dish.
Layer 1/2 of the potatoes into bottom of the prepared casserole dish. Top with the onion slices, and add the remaining potatoes. Season with salt and pepper to taste.
In a medium-size saucepan, melt butter over medium heat. Mix in the flour and salt, and stir constantly with a w whisk for one minute. Stir in milk. Cook until mixture has thickened. Stir in cheese all at once, and continue stirring until melted, about 30 to 60 seconds. Flour cheese over the potatoes.
Cover the dish with aluminum foil.
Bake 1 1/2 hours in the preheated oven.