Oven Baked Scalloped Potatoes

This is a classic scalloped potato recipe
that I learned from my Grandmother.
With russet potatoes, onions, black pepper
unsalted butter and plain old whole milk.

Ingredients:
6 russet potatoes, peeled and sliced
2 cups whole milk
1 teaspoon black pepper
1 onion, peeled and chopped
6 tablespoons unsalted butter
4 tablespoons flour

Directions:
While slicing potatoes 1/4 inch thick,
place in a large bowl of cold water.
Rinse and drain sliced potatoes well.
Butter a glass baking dish and layer
potato slices in one layer on bottom.
Dot with butter, sprinkle with flour,
salt and black pepper.
Make another layer of potato slices,
dot with butter and spread onions on it.
sprinkle with flour, salt,and pepper.
Top with another layer of potato,
onion, butter salt and pepper.
Preheat oven to 350 degrees F.
Por milk in on corner in baking dish.
Bake for one hour.
Increas heat to 400 degrees F.
Bake for another 30 minutes.
Remove and let cool some before serving.
After serving add 1/4 cup cold milk
to the leftover potatoes in the dish.
Cover with plastic wrap and refrigerate.