Chickenfeed with vegetable? Crazy! (7)
I believe the answer is:
peanuts
'chickenfeed' is the definition.
(I've seen this before)
'with vegetable? crazy' is the wordplay.
'with' says to put letters next to each other.
'vegetable?' becomes 'pea' (pea is a kind of vegetable).
'crazy' becomes 'nuts' (I've seen this before).
'pea'+'nuts' is 'PEANUTS'.
(Other definitions for peanuts that I've seen before include "Cartoon strip; tiny sum" , "pittance" , "Schulz cartoon; trifling sum" , "Bits of food" , "Snack food - comic strip with Snoopy and Charlie Brown" .)