Gentleman sent back fish dish (it's ''crumby'') (7)
I believe the answer is:
rissole
''crumby'' is the definition.
I can't judge whether this definition defines the answer.
'gentleman sent back fish dish' is the wordplay.
'gentleman' becomes 'sir' (a man may be addressed as sir).
'sent back' says the letters should be written in reverse.
'fish dish' becomes 'sole' (I've seen this in another clue).
'sir' reversed gives 'ris'.
'ris'+'sole'='RISSOLE'
'it's' acts as a link.
Can you help me to learn more?
(Other definitions for rissole that I've seen before include "faggot" , "Fried meat/breadcrumb ball" , "Lorises (anag)" , "Fried and breadcrumbed dish" , "Fried small cake of chopped meat" .)