Annetta's Scalloped Potatoes

4 cups thinly sliced pared potatoes
1/4 cup minced onion
3 TBS flour
1 tsp salt
1/4 tsp pepper
1/4 cup butter
21/2 cups hot milk

Heat oven to 350
Arrange potatoes in four layers in a 2 qt casserole or and 8X8 pan.
Sprinkle the first 3 layers with 1 tsp onion, 1 TBS flour, 1/4 tsp salt and a dash of pepper.
Sprinkle last layer with remaining onion, salt, and pepper, dot with butter.
Pour hot milk over and bake covered for 30 min.
Continue baking uncovered for 45-60 min longer.