gunkanmaki
Gunkanmaki (軍艦巻, lit. "warship roll") is a special type of nigirizushi. This is an oval, hand-formed clump of sushi rice that has a strip of nori wrapped around its perimeter to form a vessel that is filled with some soft, loose or fine-chopped ingredient that requires the confinement of nori.
See also
This tag implicates sushi (learn more).