I am a food you'd never find or certainly wouldn't eat
I don't exist, and yet I do, now isn't that a feat!
I am a good example of something that is wrong
I'm mentioned in the speech of some but more often heard in song.
What am I?
Clue 1
Because I am not real it is difficult to say
exactly what I am, although a certain Dr Hay
would tell you I'm no good because my two ingredients
should never mix together if you have any sense.
Clue 2
The best hint I can give you, without my being rude
is tell you to work backwards, because I'm not a literal food!
I certainly sound food-like, and I mentioned speech and song
If you think about those lines you'll have the answer before long!
Clue 3
I'm very disappointed that you need another clue
You really should just have a try, display some "daring do"!
So if perhaps you're biting time, afraid, or feeling flustered
Please, submit your best attempt, it might just pass mustard!