Stewing hollow nuts to eat (6)
I believe the answer is:
ingest
'to eat' is the definition.
(I've seen this in another clue)
'stewing hollow nuts' is the wordplay.
'hollow' says to hollow out the word (remove centre letters).
'nuts' is an anagram indicator (nuts can mean crazy).
'stewing' with its centre taken out is 'steing'.
'steing' anagrammed gives 'INGEST'.
(Other definitions for ingest that I've seen before include "Absorb - signet (anag)" , "How to take courses" , "Consume food" , "Swallow, absorb" , "Take (food) into the body" .)