1. Add water in a medium cooking pot and bring it to almost boiled. Once there, remove from the heat and slowly add water to reduce the heat to about 80℃ degree. Immediately add dissolved katakuriko/potato starch and mix.
2. Then gently place the eggs in the hot water using a ladle.
3. Cover and leave for about 15 min (for 2 eggs), about 20 min (for 4 eggs). Remove from the hot water and leave it about 1 minute. Then put in the cold water. (No need to add ice.)
4 Crack the egg into a serving plate (or bowl) and pour the sauce. Enjoy!
Also, serve over udon, ramen, rice, or donburi with any kind of food.
For the sauce :
In a small cooking pot, add all the sauce ingredients and bring it to a boil. Simmer for about 1 min. Let it cool, then chill in the fridge until you need.
You can enjoy onsen tamago either cold or warm, as your choice:)