Place a large skillet over medium heat. Add the bacon and cook until crisp; remove the bacon to paper towels to drain. Crumble the bacon and set aside. Wipe out the skillet.

In a mixing bowl, beat the eggs with the milk, salt, and pepper until well blended.

Melt the butter in the skillet over medium-low heat until hot; pour in egg mixture. Reduce heat. As the egg mixture begins to set on bottom and sides of the skillet, lift and fold over with a spatula. Cook until eggs are almost set; fold in the bacon and green onion, if using. Heat through and serve immediately.