On reflection consumed fine cheese (4)
I believe the answer is:
feta
'cheese' is the definition.
(I've seen this before)
'on reflection consumed fine' is the wordplay.
'on reflection' says the letters should be written backwards.
'consumed' becomes 'ate' (eating is a kind of consuming).
'fine' becomes 'f' (abbreviation).
'ate'+'f'='atef'
'atef' backwards is 'FETA'.
(Other definitions for feta that I've seen before include "Greek 8 across" , "food there" , "Crumbly Greek cheese" , "Greek salad cheese" , "Goat's or sheep's milk cheese" .)