Kombu Onigiri (昆布おにぎり, kelp-tsukudani rice ball)

Kombu is modest until you cook it twice. First it gives its body to dashi, then it comes back as tsukudani, dark, glossy, and patient enough for a picnic. That is very Japanese, this refusal to waste a good thing.

The one detail that decides kombu onigiri is dryness, though I know dryness sounds like a poor advertisement. The filling must be yielding, not wet. Reduce the soy, mirin, and sugar until the kelp shines and no loose liquid runs into the rice; wet filling makes the grains slump, while a glossy one seasons from the inside and lets the rice stay rice.

Onigiri itself is not difficult, only a little unfamiliar to the hands. Use warm short-grain rice, damp salted palms, and light pressure. You're persuading the grains to hold together, not punishing them into a brick. Tuck the tsukudani in the center, wrap the nori when you eat, and you have a stuffed bite that belongs in a lunch cloth or beside tea: plain, useful, 本物 (honmono, the real thing).