Preheat oven to 375°F.
Spray glass dish with nonstick spray. Layer potato slices and chopped onions in dish.
On stove over medium heat, melt butter into flour and mix. Remove pan from heat.
Slowly pour in milk, stirring constantly until thick. If sauce does not thicken, add another tablespoon of flour AND butter.
When you reach the desired thickness, pour in grated cheese and stir until melted.
Pour sauce over potatoes and place in oven, covered, for 30 minutes.
Remove cover and return to oven for 60 minutes or until potatoes are cooked through.
Remove from oven and Let set for 20 minutes, uncovered.
Serve.
Submitted by: Krystall Smith
