Chris said he hadn’t had scalloped potatoes since he was in high school. It was something his grandma often made. Hopefully ours was comparable.
Preheat oven to 350 degrees F. In a heavy saucepan, melt butter over low heat and whisk in flour. Cook roux 3 minutes while whisking. Add milk while continuing to whisk. Bring mixture to a boil and simmer for 5 minutes until thickened. Remove pan from heat and whisk in cheese and salt and pepper to taste.
Slice potatoes about 1/8 inch thick. In a baking dish alternate layers each of potatoes and sauce, beginning with potatoes and ending with sauce. We were able to fit in 5 layers of potatoes in two baking dishes.
Sprinkle bread crumbs on top and bake, uncovered, in oven 1 hour and 15 minutes, or until potatoes are tender and top is golden.