water for boiling
1 tablespoon baking soda
6 eggs at room temperature
50 ml cup Japanese tsuyu or soup base, such as Mizkan Bonito-Flavored Soup Base
50 ml cooking sake
25 ml soy sauce or Tamari soy sauce
25 ml mirin
Combine the water and baking soda in the pot and bring the water to boil. The water level must be deep enough to cover all eggs. When the water boils, add the eggs and cook for 7 minutes.
In a separate pan add all the ingredients in Seasoning Sauce together. Bring the sauce the boil, then remove from the heat and let cool.
When your eggs are done cooking, plunge them into ice water and leave to sit for 5 minutes. Carefully peel off the shells, while the eggs are still in the water. Make sure you remove the membrane covering the egg white.
In a container or a bag, add the Seasoning Sauce and the eggs. Gently rotate the eggs to make sure they’re evenly covered in the sauce, then leave to stand overnight, or 1 or 2 days in the fridge. When they are ready to serve, slice into halves and serve with ramen or eat as a snack.