Finished off a good gravy with peeled dates, just to be annoying! (9)
I believe the answer is:
aggravate
'gravy with peeled dates just to be annoying' is the definition.
I can't judge whether this defines the answer.
'finished off a good' is the wordplay.
I cannot quite see how this works, but
'a' is within the answer.
'good' could be 'g' (abbreviation) and 'g' is found in the answer.
'finished off' could be 'ate' (finished eating) and 'ate' is located in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for aggravate that I've seen before include "Make (a problem) worse" , "Exasperate or exacerbate" , "Make more serious" , "Annoy; make worse" , "Make a bad situation worse" .)