Three types of rolled omelettes (tamagoyaki) are served at sushi restaurants: dashi-maki tamago, kaigan-yaki tamago, and atsu-yaki tamago. Sushi restaurants don’t mix very much fish stock into their dashi-maki tamago (the most common tamagoyaki used for nigiri) because it can cause the rice to crumble. Kaigan-yaki tamago contains pieces of fish and is prepared thin. Atsu-yaki tamago is prepared with lean fish or shrimp that has been finely minced and grated. The egg whites are beaten and it resembles castella sponge cake when prepared correctly.