Start by preparing an ice bath to stop the eggs from overcooking. Bring a pot of water to a gentle boil. This ensures your eggs cook evenly and peel easily later.
In a mixing bowl, stir together soy sauce, water, sesame oil, brown sugar, garlic, green onions, chili peppers, and toasted sesame seeds. This combination forms a rich, balanced marinade.
Gently lower the room-temperature eggs into the boiling water. Boil for exactly 6 to 6.5 minutes to achieve a jammy yolk. Immediately transfer them to the ice bath to halt cooking.
Once the eggs are cooled, carefully peel them to maintain the smooth surface. Place them in your airtight container or bowl, ready for soaking in the marinade.
Pour the prepared marinade over the peeled eggs, ensuring full coverage. Place a small plate on top if needed to keep eggs submerged. Cover and refrigerate for at least 6 hours, flipping halfway through to marinate evenly.
Slice the eggs in half or serve whole over rice, noodles, or toast. Spoon some marinade over for an extra burst of flavor. These eggs are visually stunning with their glossy exterior and golden yolk.