Does everyone send in what they're told to? At our school about half of the parents send in food for the parties.
The class teacher put a piece of paper up on the wall by the door and the parents had to write their name and what they were going to bring - so we got to choose.

And my homemade sausage rolls went within 5 minutes There was a range of homemade and store bought stuff, pretty much all of it got eaten, even the fruit.