1. Cook eggs for 6 to 7 minutes, depending on the desired texture. For a soft boiled egg, cook for 6 minutes. Cook for 7 minutes for a slightly harder egg. Once cooked, plunge the eggs in a bowl of water and ice cubes to completely stop the cooking process.
2. In a plastic bag or a food container, pour tsuyu and shiokoji then mix. Peel the egg and place in the marinade. Shiokoji is optional but it will make the eggs much softer.
3. Marinate the eggs for at least half a day. If the marinade does not cover completely the eggs you can flip the eggs from time to time to allow the marinade to impregnate each side. The eggs will darken, as in the picture !
Enjoy !