8" square pan , greased
Preheat oven to 350 degrees.
Boil potatoes for about 15 minutes take out of pan and let cool.
While potatoes are cooling melt 2 tablespoons butter in small sauce pan,
gradually stir in two tablespoons flour.
When mixed slowly add 1-1/2 cups milk, stirring to keep smooth.
Bring to boil take off heat when it starts to thicken.
Peel two potatoes and slice to cover bottom of pan.
Next, add part of the onions, the cheese and 1/3 sauce;
continue layers ...
Bake 45min to 1 hour uncovered until slightly brown and bubbly.