Delicacy to complement sour vegetable? (9)
I believe the answer is:
sweetmeat
'sour vegetable?' is the definition.
The answer and definition can be both things that one consumes for nourishment as well as being singular nouns.
Maybe you can see a link between them that I don't see?
'delicacy to complement' is the wordplay.
'delicacy' becomes 'sweet' (sweet is a kind of delicacy).
'to complement' becomes 'meat' (I am not sure about this - if you are sure you should believe this answer much more).
'sweet'+'meat'='SWEETMEAT'
(Other definitions for sweetmeat that I've seen before include "Perhaps rock" , "Tasty item" , "Former item of confectionery" , "Confectionery - we eat stem (anag)" , "fancy cake?" .)