I make this a lot for work breakfasts. Our favorite combo is Ritz crackers and Swiss cheese, but you can use whatever kind of cracker/cheese combo you like. Sometimes I fry 6 slices of bacon crisp and crumble it over the pie crust. Then I saute the onions in the bacon fat instead of the oil. It freezes well if there are leftovers, just put the frozen slice into the oven at 350 for about 20 minutes or so. Enjoy.