SAUSAGE! The writer's unfortunately upset (6)
I believe the answer is:
salami
'sausage' is the definition.
(I know that salami is a type of sausage)
'writer's unfortunately upset' is the wordplay.
'writer's' becomes 'I'm' ('I am' referring to the writer of the clue).
'unfortunately' becomes 'alas' ('alas' is used to express regret).
'upset' is a reversal indicator.
'im'+'alas'='imalas'
'imalas' reversed gives 'SALAMI'.
'the' is the link.
(Other definitions for salami that I've seen before include "Highly-seasonal sausage" , "Savoury snack" , "Garlic- flavoured sausage" , "Slim, graceful" , "Sausage served sliced" .)