After I went to bed I started thinking that maybe they are not baby squash and looking closer I think they are some kind parboiled tuber. Possibly one to be eaten al dente like Jersualem Artichokes which accounts for the undercooked look.
None of that excuses the carrot though. I can see 7 now.. "a bright color is required to supply a pleasing balance to this dish." Places carrot on plate. Shoving a small dead bird into a vol au vent case is shoddy cuisine, I thought those things vanished with the 80's.
I'd almost expected something in matching primary and secondary colours for contrast' sake. And those yellow things: I am pretty sure its raw potatoes, cut in this fancy diamond shape. The writers (or whoever is responsible for these things) thought, that no one has seen raw potatoes for years, since you can buy them boiled. And certainly not such small ones.
If you pay a little attention to what usually can be found in Neelix' kitchen, you realise it is not very exotic. Those light purple eggplants, dark plums, strawberries...
The processed food on the other hand was always very creative IMO: especially the names. Maybe we should scan the show for some ideas for next weekends dinner!