The name of the egg is wrong. That thick egg sushi topping is not called dashi-rolled egg (dashimaki tamago). That's just a "tamagoyaki". Like getting it wrong kinda makes the dialogue make zero sense because dashimaki tamago does not use fish. Granted, this is the more common version these days, so a lot of the time when you say tamagoyaki you do get the dashimaki. Regardless, not all tamagoyaki are dashimaki tamago.
That particular version of thick-cut tamagoyaki that uses fish as he described is baked and looks more like a cake at the end (
Youtube demonstration). It's not rolled.