Allow cook to prepare starter in batter (6)
I believe the answer is:
wallop
'batter' is the definition.
(I've seen this before)
'allow cook to prepare starter' is the wordplay.
'cook' is an anagram indicator.
'to' means one lot of letters go next to another.
'starter' suggests taking the first letters.
The first letter of 'prepare' is 'p'.
'allow' is an anagram of 'wallo'.
'wallo'+'p'='WALLOP'
'in' is the link.
(Other definitions for wallop that I've seen before include "Best" , "Thump" , "big hit" , "Strike very hard" , "batter" .)