Intention of putting nothing extra into supper concoction (7)
I believe the answer is:
purpose
'intention' is the definition.
(I know that intention can be written as purpose)
'putting nothing extra into supper concoction' is the wordplay.
'putting nothing extra' becomes 'o' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'into' means one lot of letters goes inside another.
'concoction' indicates anagramming the letters.
'supper' anagrammed gives 'purpse'.
'o' placed into 'purpse' is 'PURPOSE'.
'of' acts as a link.
Can you help me to learn more?
(Other definitions for purpose that I've seen before include "Aim, intention, design" , "End" , "Motivation or intention" , "Resolve; reason" , "Resolve, objective" .)