Jelly with a distinctive flavour mostly (5)
I believe the answer is:
aspic
'jelly' is the definition.
(I know that aspic is a type of jelly)
'distinctive flavour mostly' is the wordplay.
'distinctive' becomes 'a' (I am not sure about this - if you are sure you should believe this answer much more).
'flavour' becomes 'spice' (spicing is a kind of flavouring).
'mostly' means to remove the last letter (most but not all of the word).
'spice' with its last letter removed is 'spic'.
'a'+'spic'='ASPIC'
'with a' acts as a link.
Can you help me to learn more?
(Other definitions for aspic that I've seen before include "Ending of Marlowe's thriller" , "Savoury jelly for coating meats and eggs" , "stock production" , "Clear meat or fish jelly" , "Glaze" .)