, shirasu are the young of sardine
s. It literally means 'white child' or 'white small.' They are thin, transparent fish
about 1 centimeter
Raw shirasu is often eaten with sake (or beer, recently), much as cheese is eaten with wine. The slightly bitter fish are mixed with grated ginger, chives and soy sauce, or with wasabi and soy sauce.
Boiled shirasu are sold in supermarkets in packs of hundreds. When boiled, the shirasu become opaque. The Japanese put them on steamed rice with a little soy sauce (much like natto). It's delicious, and doesn't require an 'acquired taste' like natto does. Boiled shirasu are also eaten with daikon oroshi (grated radish).
Boiled and sun-dried shirasu are called chirimen or chirimen-jako. Often, the sun-drying is done right on the beach by the fishermen. Chirimen-jako is very versatile and used in many dishes. Chirimen is frequently an ingredient in furikake.
Shirasu dried together in flat mats are called tatami-iwashi. Tatami-iwashi is also eaten with sake. To prepare, grill lightly over an open flame, cut into small pieces, and add a little soy sauce. You can also add warm water to tatami-iwashi and use it in clear soup.
Shirasu is high in calcium, vitamin D, and protein. Needless to say, they're very healthy.