Dish, South American, hot chili – at last! (5)
I believe the answer is:
sushi
'dish' is the definition.
(sushi is a kind of dish)
'south american hot chili at last' is the wordplay.
'south american' becomes 'sus' (I've seen this in other clues).
'hot' becomes 'h' (abbreviation eg on taps).
'at last' suggests the final letters.
The final letter of 'chili' is 'i'.
'sus'+'h'+'i'='SUSHI'
(Other definitions for sushi that I've seen before include "Japanese vinegared rice dish" , "Japanese rice and raw fish dish" , "Raw fish dishes" , "Rice and raw fish wrapped in seaweed" , "oriental dish" .)