(water and brown sugar can be adjusted to taste, i.e. to make eggs less salty or more sweet)
Instructions
Boil eggs until soft or hard boiled to your preference. Remove shells. Rinse with water to remove any tiny shell fragments. Set aside.
In a small pot, bring shoyu to a boil. Turn off heat. Then add eggs. Using a rubber spatula or wooden spoon (so that the eggs don't become nicked) gently roll the eggs around coating the egg. Note: for Bebe's shoyu tamago, I barely steep the egg in the shoyu (less than a minute), but for my own, I will continue to steep and "color" the egg for a few minutes.
Continue to "color" the eggs with shoyu until desired color/saltiness. The eggs and shoyu marinade may be transferred to a glass storage container and placed in the refrigerator. Turn the egg periodically in the container until desired color/boldness of flavor.
Once you've reached the desired "boldness" of shoyu tamago, discard shoyu mixture (I store excess shoyu in the fridge for cooking) and enjoy your shoyu tamago.
Recipe by Bebe Love Okazu at https://bebeloveokazu.com/2014/01/22/shoyu-tamago-soy-sauce-eggs/