6 large all-purpose potatoes, peeled and sliced very thin
2 large yellow onions, peeled, sliced thin and separated into rings
1 1/2 teaspoons salt
1/4 teaspoon pepper
4 tablespoons flour
4 tablespoons butter
2 1/2 cups milk (approximately)
Layer half the potatoes into a well-buttered 9-by-9-by-2-inch baking dish, cover with half the onions rings, sprinkle with half the salt, pepper and flour, then dot with half the butter.
Make a second layer precisely the same way, ending up with flour and butter.
Pour in milk just until it is visible in the potatoes – it should not cover them.
Bake uncovered in a slow oven (300 degrees F.) for about 1 3/4 to 2 hours or until potatoes are nicely browned on top.
Makes about 6 servings.