So ... Perrine does seem to like it when, on relatively rare occasions, I give her moist food from a can or a pouch instead of her usual dry food. She likes the gravy. She licks up the juices quite thoroughly, spending longer at her dish than she usually does at a time ... and maybe takes a bite or two of the solids if it's from a can, and carefully leaves behind every morsel of then-dry solid food if it's from a pouch. Likes her gravy, she does.
A couple of times I've offered her a taste of the liquid from a can of seitan, and she's responded as though I'd given her kitty-crack. Is it the spices, the salt, the mouth-feel? I don't know, but there's certainly nothing especially carnivore-friendly in there aside from the salt. That liquid makes a better bribe than any commercially packaged kitty-treats.
As long as I'm babbling about my darling cat ... she sometimes complains about stuff -- sometimes I can tell what she's complaining about and other times I can't; there's a particular squeak and body language that I suspect means she just woke up from a bad dream -- but it seems that regardless of its relevance to whatever was bothering her, a really enthusiastic scritching or a session with the slicker brush answers pretty much any complaint.