u/Eighter16rus

Today I was in a sushi shop in Busan, and they had a lovely nigiri (tried cuttlefish for the first time btw)

But there was this strange-looking sushi in their sets. I'm not sure if it's a fish or something else, but curious to find out.

It was slippery, rather dense meat (or whatever), with a taste kinda similar to that of soft roe (shirako in Japanese sushi) but this brown color is clearly different from the roe's.

Does anyone know what was it?