Starter rich and intense, treated as Indian side dish (5)
I believe the answer is:
raita
'indian side dish' is the definition.
(I know that Raita are Indian)
'starter rich and intense treated as' is the wordplay.
'starter' indicates taking the first letters.
The first letters of 'rich and intense treated as' is 'RAITA'.
(Other definitions for raita that I've seen before include "Indian dish of chopped cucumber and yoghurt" , "Indian recipe" , "fare from India" , "yoghurt dish from India" , "Dishy thing" .)