My sim just made some beef pet food but you cant seem to do anything with it. Does anyone know if there is a glitch?

If you click on an empty food bowl, you should have the option to "fill with gourmet food", which is the homemade stuff in your sim's inventory.

I have the same problem, one of my sims - that's a genie in fact - magically made some "beef pet food" and allow me to emphasize it's "beef" pet food, not gourmet pet food

it's not in the inventory, it's like any plate, out on a surface, a counter or a table, that can be moved in buy/build mode, but in gameplay mode, there is nothing apparently I can do with it

I'll try filling out an empty bowl, but so far, at the time of writing this message, I had no empty bowl to try, but I'll buy an empty one and try it ASAP