Irish writer working to consume cheese (6)
I believe the answer is:
obrien
'irish writer' is the definition.
(I've seen this before)
'working to consume cheese' is the wordplay.
'working' becomes 'on' (on can mean working or activated).
'to consume' indicates putting letters inside.
'cheese' becomes 'brie' (Brie is an example).
'on' enclosing 'brie' is 'OBRIEN'.
(Other definitions for obrien that I've seen before include "'Kate ..., Edna ..., (1'5)'" , "Flann -, Irish novelist" , "I be Ron, strangely, with this surname" , "Edna, novelist" , "Irish writer" .)