When we first eat outside of the family kitchen, we realize that there is a whole different world of flavors out there. Most of the time, however, the flavors we end up longing for are the comforting tastes of the hearth that nurtured us. It's funny that even when we encounter the same dish, in new versions that we consider far superior to that of our childhood, we still pine for the combination of flavors that sends us back to those days when our palate was first developing.
As is often the case with foods made at home, slight variations in simmering can yield different results and unique flavors. For many Japanese, simmered dishes — especially fish — fall into this category of home-cooked comfort foods. Often when Japanese go abroad and begin the invariable search for the flavors of home, the dishes they report that they miss the most are those that can't be found in many restaurants abroad. Sushi, sukiyaki and questionable versions of teriyaki are most readily available. Noticeably absent from most Japanese restaurants overseas are these simple simmered ni-mono.
In a native restaurant setting, most simmered fish is cooked to order and served piping hot. In smaller cafeteria-like shokudo counters, fish simmered earlier in the day might be zapped in the microwave before being served. At home you may do as time permits and simmer your fish just as your family sits down to eat or right when your guests arrive, or you may simmer things up to a day in advance and refrigerate, rewarming when it's time to eat.