Sailor tucking into cereals cooked with a vegetable (9)
I believe the answer is:
calabrese
'a vegetable' is the definition.
(I've seen this before)
'sailor tucking into cereals cooked' is the wordplay.
'sailor' becomes 'ab' (abbreviation for able seaman).
'tucking into' indicates putting letters inside.
'cooked' indicates an anagram.
'cereals' is an anagram of 'calrese'.
'ab' put within 'calrese' is 'CALABRESE'.
'with' acts as a link.
(Other definitions for calabrese that I've seen before include "Vegetable" , "Variety of broccoli" .)