Gag on tandoori chicken hot starters (5)
I believe the answer is:
retch
'gag' is the definition.
(I've seen this before)
'on tandoori chicken hot starters' is the wordplay.
'on' becomes 're' ('on' can be mean 'with reference to'**).
'starters' suggests taking the first letters.
The initial letters of 'tandoori chicken hot' is 'tch'.
're'+'tch'='RETCH'
(Other definitions for retch that I've seen before include "Heave (as if to vomit)" , "Try to vomit" , "Strain as if to vomit" , "Try to be sick" , "Unsuccessful effort to vomit" .)