Tiny amount of French potage given to prisoner (7)
I believe the answer is:
soupcon
'tiny amount' is the definition.
'french potage given to prisoner' is the wordplay.
'french potage' becomes 'soup'.
'given to' says to put letters next to each other.
'prisoner' becomes 'con' (abbreviation for 'convict').
'soup'+'con'='SOUPCON'
'of' is the link.
(Other definitions for soupcon that I've seen before include "Dash" , "suspicion" , "Tiny quantity" , "Hint" , "very little" .)