Thanks to "anonymous" who posted a comment to my
recent post about "Christmas Tinner" (the entire Christmas day meal in a tin), alerting me to this video in which "steviejacko" has a can of the stuff, opens it up, and eats it.
This suggests that, at the very least, someone created a prototype of this product.
In the youtube comments, steviejacko says: "The one shop where it is available in basingstoke is sold out, it was done as a trial to see how much interest there was, it wont be available now for 2 weeks and even then it will be pretty scarce."
Comments
https://www.youtube.com/watch?v=K-mfYXdjNTM&list=PLuXVJtG6oNtG8ViYjazh_oLw8Km8yWYDY&index=12