This is probably wrong, but I've learned that
- Occasionally the 'probably wrong' answer is actually right, and
- A wrong answer may give others helpful insight.
So here goes:
FIRE, BLACK, DESTROY
These are all synonyms for 'break/remove/separate'
GRAVY, MAYONNAISE, BUTTER
These are all things you 'spread'
The main roast:
POISON, SALMONELLA, DISGUST
These are all things which are 'bad or terrible'; in fact, awful
So what happens if we take the main roast, and
break it apart and spread it out?
A W F U L, or if you slur your speech, "a wuful", that is, "a waffle"
Why was it messed up?
I suppose because you roasted it? Don't roast waffles. They should go in a toaster.
Why was it 'inevitable, inedible, terrible', and negative?
Inevitable means 'absolutely certain'. Whereas to waffle is to be absolutely uncertain. This is the exact opposite, or negative/inverse meaning.
Inedible is what you get when you roast a waffle. That'd be a pretty negative experience.
Terrible means 'awful'. A word with negative connotations which has been addressed already, perhaps reiterated here as a hint.
As for 'shchiekcemn', what is that?
That one is easy. It's the Rot13 of 'fupuvrxprza' ; )
So in conclusion:
Don't roast waffles. Or else find the actual answer to this puzzle. : )