He may work in a gallery (5)
I believe the answer is:
miner
'he' is the definition.
'work in a gallery' is the wordplay.
I cannot quite understand how this works, but
'in' is within the answer.
The remaining letters 'mer' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'may' is the link.
Can you help me to learn more?
(Other definitions for miner that I've seen before include "it's the pits, for me" , "Underground labourer" , "Underground worker" , "Burrowing insect" , "Person who works underground" .)