Soy Sauce :Sake (or White Wine):Mirin = 1:1:1
1 Grind the onions and leave them in a strainer or sieve to drain.
2 Put onions in a heated frying pan with some oil.
3 Cook for 20-30 mins until they have browned and are sweet in taste.
4 Pour on the sauce and mix well with the onions. Simmer for a while with low heat and then it is finished.