Fill a medium pot with water and bring it to a rolling boil. Gently add fresh eggs and cook for 6–7 minutes for soft-boiled yolks.

Transfer eggs to a bowl filled with ice water and let them sit for about 5 minutes to cool.

Carefully tap eggs to crack the shells and peel them under running water.

In a mixing bowl, whisk together soy sauce, water, sugar, rice vinegar, sesame oil, minced garlic, sliced green onions, and chopped chili pepper if desired.

Place peeled eggs in a clean jar, pour the marinade over the eggs, ensuring they are fully submerged.

Seal the container and refrigerate for at least 6 hours, preferably overnight.

Remove eggs from the marinade, slice in half, garnish with green onions and sesame seeds, and serve.