Scalloped Potatoes in the Oven or Slow Cooker

about 2 lbs potatoes, any variety (I used 7-8 good sized red)
2 T butter
2 T flour
2 C hot milk
salt and pepper

Scrub the potatoes.  You can peel them or leave the peels on.  Slice thinly.  (I love my Rada Cutlery Cook’s Knife for this job.) Melt the butter over medium heat in a skillet.  Stir in the flour and cook for a minute or two.  Whisk in the hot milk.  Keep whisking until smooth.  Cook until bubbly and slightly thickened.  Season with salt and pepper. Butter the crock of a slow cooker or a casserole dish if you’re using the oven.  Put in the potato slices.  Pour sauce over the potatoes. Cook on low for seven to eight hours or high for five to six hours.  Or bake uncovered at 350 degrees for 1 1/2 hours or until the potatoes are tender when poked with a fork.