Scalloped Potatoes

I grew up eating scalloped potatoes as a side dish. I never seem to make them quite the same way as my grandma does....but they are delish nonetheless. Often times, I will add diced ham and some very thinly sliced onion to it and make it a main dish with a salad and steamed veggies. Keep in mind that the measurements are approximate and may need to be adjusted a little since it is one of my grandma's recipes and she doesn't measure well. She just throws stuff together and it always turns out good!

6 medium potatoes
4 Tablespoons butter
4 Tablespoons flour
1 teaspoon salt
2 1/2 cups milk
1 1/2 cups grated cheddar cheese
black pepper to taste

Peel potatoes and slice thin. (I leave the peel on) Make a white sauce out of the butter, flour, salt, and milk. Stir until thickened and remove from heat. Add grated cheese. Place potatoes in a greased casserole dish. Cover with hot cheese sauce. Cover and bake at 375 degrees for 1 1/2 hours. Check after 1 hour and leave the foil off for the last little bit of baking so that the cheese can brown on top.