Dictator, unfortunately upset, finally spurned cold food (6,5)
I believe the answer is:
caesar salad
'cold food' is the definition.
(salads are usually served cold)
'dictator unfortunately upset finally spurned' is the wordplay.
'dictator' becomes 'caesar' (I've seen this in another clue).
'unfortunately' becomes 'alas' ('alas' is used to express regret).
'upset' says the letters should be written backwards.
'finally' says to take the final letters.
The last letter of 'spurned' is 'd'.
'alas' back-to-front is 'sala'.
'caesar'+'sala'+'d'='CAESAR SALAD'
(Other definitions for caesar salad that I've seen before include "Dish containing lettuce" , "Seasoned mixture of cos lettuce and croutons" , "food" , "Dish of dressed lettuce with croutons" , "leaves meal - with 14a" .)