Occasion where French is accommodated for balance (4,3)
I believe the answer is:
even out
'balance' is the definition.
(I know that even out is a more specific form of the action balance)
'occasion where french is accommodated' is the wordplay.
'occasion' becomes 'event' (I've seen this before).
'where french' becomes 'ou' ('where' in French).
'is accommodated' means one lot of letters goes inside another.
'event' enclosing 'ou' is 'EVEN OUT'.
'for' acts as a link.
(Other definitions for even out that I've seen before include "reach consistent level" , "Make less varied" , "Leave flat" , "Make level" , "iron?" .)