I like vinegar, so I prefer the combination of soy sauce and vinegar to salt and pepper. The sweetness of onions and the nice flavors of vinegar, and the fragrance of butter and soy sauce are bound to go together. I often make this dish for my lunch, or when I need one more side dish.

Stir fry the onions until they get really soft. Adjust the seasoning if the taste is too light depending on the size of onion and its water content. Heat over medium heat as not to burn the butter. Recipe by Osshosan