This is ingredients for this sauce: water, soy sauce, sugar, vinegar (just a little), sesame oil, green onion, onion, sesame seeds. You can add chili, but I didn't put in 'cause my babies cannot eat spicy.
Eggs s/b soft-boiled, I boiled soy sauce and water with sugar, then add vinegar, chopped onion, green onion, sesame seeds and oil when soy sauce was warm (not hot). Put eggs into container and pour sauce, keep in few hours then you can serve with hot rice.
I dont have detail recipe, taste is based on our family taste :). You can try and adjust 😊