In a medium saucepan, add soy sauce, mirin, garlic, chili-flakes, ginger, sesame oil and 2 cups of water and bring to a boil over med-high heat.
Once boiling, reduce heat to low and simmer for 5 minutes.
Let cool for about 10 minutes.
Peel your soft-boiled eggs.
Drop eggs in marinade and let sit for 30 minutes in saucepan.
Place eggs & marinade in an airtight container and marinade in the fridge for at least three days, and up to 2 weeks.
