Starters of soup unusually served hot in cold dish (5)
I believe the answer is:
sushi
'cold dish' is the definition.
(type of Japanese dish)
'starters of soup unusually served hot in' is the wordplay.
'starters of' says to take the initial letters.
The initial letters of 'soup unusually served hot in' is 'SUSHI'.
(Other definitions for sushi that I've seen before include "Japanese cold rice dish" , "Japanese rice and raw fish dish" , "Fated" , "oriental dish" , "Raw fish dishes" .)