I need to crumble a few into the vegetable (6)
I believe the answer is:
endive
'the vegetable' is the definition.
(endive is a kind of vegetable)
'i need to crumble a few into' is the wordplay.
'to crumble' indicates an anagram.
'a few' becomes 'v'.
'into' means one lot of letters goes inside another.
'i'+'need'='ineed'
'ineed' with letters rearranged gives 'endie'.
'endie' enclosing 'v' is 'ENDIVE'.
(Other definitions for endive that I've seen before include "salad ingredient" , "Veined (anag) - salad plant" , "Salad plant with crisp curly leaves" , "Envied the salad green badly" , "Salad plant related to chicory" .)