Slice the onion into thin strips (5mm width).

Lightly beat the eggs in a bowl to make beaten eggs.

In a small frying pan, combine the seasoning ingredients (mirin, white dashi, water) and onion. Heat over medium heat until boiling.

Cover with a lid and simmer over low heat for about 5 minutes.

Remove the lid and pour half of the beaten eggs into the pan. Cover again and cook for about 1 minute.

Remove the lid and pour the remaining beaten eggs into the pan. Cook over low heat for 1-2 minutes until desired firmness.