To make the cheese sauce: melt the butter, stir in the flour and add the milk to make a rue sauce. Stir until thick. Add salt and pepper to taste. Once the mixture begins to thicken, add the cheese and stir until melted; set aside. Chop the bacon and sauté until limp. Add the onions and peppers and sauté until soft. Beat the eggs and add to the bacon, onions and pepper mixture. Turn lightly to scramble. After the eggs begin to set, fold the cheese sauce in carefully. Spray a 13×9 pan with cooking spray and press the thawed hash browns into the bottom of the pan. Transfer the egg mixture to the pan to top the hash browns. Let sit overnight in the refrigerator. Bring to room temperature and bake at 350 degrees for about 35 minutes or until bubbly. Serve and enjoy!