Well, so far its been all good on Pennys (boring) new diet. Im not sure she thinks its boring, but I do, so Im thinking of ways to make the Royal Canin Gastro Intestinal Low Fat Diet seem interesting.
As I mentioned previously, Ive been putting it into a Nina Ottosson dog toy. Thats fine, and it slows Penny down so much that she takes more than three minutes to get the food out of the toy. (Only half the recommended serve, because Im boiling up a half serve of chicken and rice each time.)
Now Ive come up with the idea of buying the same food in a can, and stuffing some into a Kong. I think Penny would vote this a good idea.

Also, Ive baked some of the can into crunchy treats, which makes it easier to reward good behaviour and practise tricks.
The instructions on this site explain how to cut the top and bottom off a can and use the cut-off lid to push the food out slowly, in order to slice it evenly and thinly.

Its rather mushy food, so without the idea of pushing it out gently, I dont know how Id have been able to make slices.

Here are the slices ready for baking.

I did them for about thirty minutes at 180°C. And after enduring the smell that humans would consider pretty awful, put them outside the house to cool down.

Today she sampled them, and seemed to love them. (On the other hand, she loves beef, kangaroo, chicken, rice, red peppers, banana, duck poo, possum poo, stinky buried bones, compost, and anything else you can suggest, so maybe its not altogether surprising she liked my baked treats.)