Preheat the oven to 350 degrees. Coat a mini baking dish with cooking spray.
Mix the eggs with the milk until well combined then season with sea salt and freshly cracked pepper, to taste. Place a few pieces of bacon, tomato slices, sharp cheddar, and green onion into the mini baking dish.
Pour the egg mixture into the baking dish then place the remaining bacon, tomato slices, sharp cheddar, and green onion on top.
Place into the oven and bake for 25-30 minutes, or until a tester inserted into the center comes out clean. Remove from the oven and serve immediately. Enjoy.