Here in Paris no good? Topping! (5)
I believe the answer is:
icing
'topping' is the definition.
(I know that icing is a type of topping)
'here in paris no good?' is the wordplay.
'here in paris' becomes 'ici' (I've seen this in another clue).
'no good?' becomes 'ng' (abbreviation).
'ici'+'ng'='ICING'
(Other definitions for icing that I've seen before include "Sweet coating on cake" , "effect of cold weather" , "that finishes off 29 [ANGEL CAKE]" , "white coat" , "it's dangerous on the roads" .)