Makes a secret concoction (7)
I believe the answer is:
creates
'makes' is the definition.
(creating is a kind of making)
'a secret concoction' is the wordplay.
'concoction' indicates anagramming the letters.
'a'+'secret'='asecret'
'asecret' anagrammed gives 'CREATES'.
(Other definitions for creates that I've seen before include "Produces" , "Generates" , "coins" , "Makes" , "Brings into existence" .)