The lines are part of a Rhysling-nominated poem, "Corrected Maps of your City", by Kendall Evans and David C. Kopaska-Merkel. Those lines, however, threw me right out of the verse. It sounded too mundane, too normal to evoke the weird alternate reality for which the poets were clearly aiming. I have eaten some version of this dish - if the beef taste is allowed to come from beef broth or lumps of the meat, and rice is Forbidden Rice, a clearly purple rice.
I'm particularly glad to have heard from those of you who answered "That sounds like made-up food from an alternate universe." It's reassuring to know that they would have worked as intended for at least a third of you, possibly more if you hadn't had time to think through it so much in advance.
Here is a bit more of that verse (it's a longer poem) for context:
The cook, behind a bamboo screen,
And maybe he possesses
The zebra fish sashimi has hooves
But no internal organs
The rice is purple
Tastes like beef...
I realize I never double-checked the cook's body parts: antennae, not tentacles, although tentacles may have stuck with me because of the fish in the next line. It really was interesting to consider how useful tentacles would - or would not - be as limbs on a cook. Antennae are, obviously, rather different in terms of what they add to a chef's capabilities. More apt for determining the sound, and thus the texture, of the food, perhaps?
Looking back, I realize I had already been pushed half out of the verse by the word "zebra" before I ever came to the rice. I didn't know how I should be hearing the word in my head: American- or British-style.