Whisk together a few eggs with soy sauce, mirin, onion powder, salt and pepper. Heat a Tamagoyaki pan to medium heat. Spray the pan with olive oil. Add some of the egg mixture and wait until it cooks a bit. Add a string cheese stick to the top. Fold over the egg and then place it back at the top. Respray the pan with olive oil. Add some more egg to the pan connecting the new egg layer with the cheese filled rollup. Place down a small piece of bacon. Roll it up again and repeat this process a few more times. Cook the egg for an additional 30 seconds to a minute to seal the egg and slice into 4 pieces.
