Bakudan Onigiri

Bakudan onigiri is a rice ball from the Oki islands, rolled large and round and wrapped entirely in rock seaweed, a look said to have earned it the name "bakudan," or bomb. The rock seaweed has thick fibers, a satisfying crunch, and a strong aroma, and even a plain rice ball with no filling carries plenty of flavor from the seaweed alone, releasing a rich oceanic scent with every bite.

Rock seaweed is lightly toasted until it turns slightly greener, then brushed with soy sauce on one side. The soy sauce side is wrapped around the rice ball to finish, and while some versions include a filling, plain ones with nothing inside are more common. The seaweed harvest runs from December to February, in the cold north wind, and once gathered it is cleaned of small stones and other debris before being pressed into sheets.

The Oki islands, made up of four main islands and more than 180 smaller ones, are surrounded by water rich in a variety of seaweeds. Gathering rock seaweed from the rocks at the water's edge on calm days, a practice called "nori tsumi," is said to be a familiar mark of winter in Oki. Most of the harvest is consumed locally, and because it is also an essential ingredient in the New Year dish "rock seaweed zoni," it is treated as a valuable local food — one reason bakudan onigiri, which uses the seaweed generously, is said to have become a common item for packed lunches and snacks.