Nigiri

Nigirizushi or Nigiri is the most traditional form of sushi and consists of a single topping over a palm-pressed compact oblong sushi rice. Any small hand-pressed sushi using your palm belongs to this category.

The two ingredients must perfectly match flavors and textures. 

Nigiri sushi is considered a simplistic delicacy in Japan, contrasting to the complicated sushi rolls enjoyed here in the West.