Gastronome Plikk does not sell items
Plikk's Food Form Manipulator and Plikk's Fluid Gas Infuser
Gastronome Plikk First Tab, Second Tab and collection status
I had the same problem and it took some time to find the solution:
You have to have Filet of Sous-Vide Meat in your inventory.
Thank you very much
Now back to Harvesting Lesson
Not only that, you need to talk to asuran master culinarian again before returning to plikk. It's easy to skip a step here, and it's not really apparent that it happened at this point, because nothing will tell you this.
It took me around 15 minutes and 2 additional Filets crafted to realize that.
The whole point of a social game is to play with the people you want to play with, not be forced to play with the people you don't.
I have them in my Achievements now, but the image has gone to a default pile of coins, not Plikk's tools. Even on wiki it's all crossed out saying it doesn't exist. It's not in my kitchen yet either.