 Tamagoyaki is served around the world in the form of nigiri, and also appears in many types of sushi rolls.In the days when most sushi establishments made their own tamagoyaki, known as gyoku in sushi parlance, connoisseur customers would order the tamago sushi prior to starting their meal to assess the sushi chef's skills.Large "futomaki" rolls often use "tamagoyaki" as an ingredient.