Sushi when the tuna runs out

San Francisco chef James Corwell says he got the idea for his tomato sushi when visiting  the Tsukiji fish market in Tokyo. Two football-field sized warehouses full of tuna made Corwell wonder how the oceans could ever keep up with the incredible volume of tuna that is sold in just one day.

Corwell writes on his website:

The answer is “They can’t.” According to a study published in the journal Nature, 90% of all large predatory fish (like tuna) are already gone, and the rate of fishing isn't slowing down.

So, when he was given the challenge of making some vegetarian sushi for a client, Corwell started working on something that could make a difference to the world’s oceans: Tomato Sushi.

Corwell's production was described by America's National Public Radio as  a dead ringer for Ahi tuna sashimi. 

It cuts into glistening slivers that are firm and juicy. And it's got a savory bite. ... To make this Tomato Sushi, he skins and removes the seeds from fresh Roma tomatoes. Then he vacuum seals them in sturdy plastic bags and cooks them in hot water for about an hour — a technique called sous-vide.The process firms up the tomatoes and creates a texture similar to tuna. Corwell throws in a few more ingredients (he won't divulge what they are), and slices them up. When eaten with sushi rice, nori, ginger, soy sauce and wasabi, they're delicious.