1.. Place bacon in a large, deep skillet. Cook over medium high heat until evenly brown. Drain, crumble and set aside.
2.. Preheat oven to 350 degrees F (175 degrees C). Lightly grease a 9 inch pie pan.
3.. Line bottom of pie plate with cheese and crumbled bacon. Combine eggs, butter, onion, salt, flour and milk; whisk together until smooth; pour into pie pan.
4.. Bake in preheated oven for 35 minutes, until set. Serve hot or cold.
Could use different meats (e.g. ham) or cheese. Leftovers make great lunches!