"Do you think drinking saltwater counts as a kind of sushi?"
"Why on Earth would it?" She wrapped her chopsticks around a ginger-painted trilobite.
"It's the one element that all of the different varieties of sushi have in common. Nothing matches taxonomically or geographically except the medium of their habitat."
“That's a pretty weak justification," she replied. "Besides, saltwater is much better seared or blackened than raw."
He laughed. She didn't.
"Well," he struggled to fish an fumbled roll from his ramekin of soy sauce. "If you're heating it before serving, doesn’t that just make it sort of a brine, or a broth?”
"Not really. To sear it, you just toss it in a pan and flip it a few times so that it only cooks around the edges. As long as the center stays raw, it shouldn't actually boil.”
"Oh.” He gave up on the errant roll, which had dissolved into a pool of rice and mush. “I have to admit, I didn't realize that was actually possible.”
"I'm not surprised. It's not an art that's easily accessible above sea level. You need water that's been thickened by deep, oceanic pressure. The abyssopelagic stuff. Some of the less legit places will mix in a few drops of squid ink to fake the darkness, but the genuine article’s texture is unmistakable. It's what you might imagine biting into a raindrop would be, if it were composed entirely of surface tension. You can’t get that kind of water up here. Most of the restaurants that offer it are so far down that they have to be legally classified as research submarines.”
Though it all seemed absurd to him, his intrigue had eclipsed his doubt. "What does that even taste like?"
“It has this beautifully paradoxical flavor, like fire and water on your tongue simultaneously; but, to be honest, all that’s mostly masked by the salt."