Try eating the whole vegetable (7)
I believe the answer is:
shallot
'vegetable' is the definition.
(thesaurus)
'try eating the whole' is the wordplay.
'try' becomes 'shot' (shot is a kind of try**).
'eating' is an insertion indicator.
'the whole' becomes 'all' (I've seen this before).
'shot' enclosing 'all' is 'SHALLOT'.
(Other definitions for shallot that I've seen before include "Type of onion" , "One may get into a stew" , "Scallion" , "It resembles an onion" , "bit of salad" .)