Boil the eggs

• Bring the water to a boil in a saucepan and add a splash of vinegar.
• Gently lower the eggs into the boiling water.

Cool in an ice bath

• Pull the eggs out after exactly 7 minutes and transfer them to an ice bath to cool.

Make the marinade

• Combine the water, soy sauce, mirin and sugar in a bowl and stir until the sugar dissolves.

Peel the eggs

• Crack the cooled eggs and carefully peel off the shells.

Marinate

• Drop the peeled eggs into the marinade and let them sit in the fridge.
• After a couple of days they are ready; serve with a drizzle of sesame oil.