"This has been a Christmas morning tradition in my family for over 25 years. The ingredients are so simple; I think that is what makes it so delicious! It would NOT be Christmas without this casserole. Make this night before."
Sauté bacon, butter and onion till tender. Add eggs, sauté until curds (they should still be very moist and not dried out). Set aside while you make cheese sauce (this step helps to firm up the eggs more without drying them out) Remember, the eggs will continue to cook in the pan, so watch to be sure you don't overcook them.
To make Cheese Sauce, melt butter in a pan, mix in flour, when flour is mixed, add milk and cheese. Stir until thickened.
When eggs are set and cheese sauce is thickened, stir in Cheese sauce – if not adding cheese, it becomes a white gravy and is still delicious. Spoon into greased 9x13 pan. Sprinkle topping and Cover and chill overnight.