"It's a dead ringer for Ahi tuna sashimi. It cuts into glistening slivers that are firm and juicy. And it's got a savory bite."

"But this flesh-like food is not fish. It's made of tomato, and it's what San Francisco chef James Corwell hopes could be one small step toward saving imperiled species of fish, like bluefin tuna."

"'What I want is to create a great sushi experience without the tuna,' Corwell tells The Salt."

"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."