Flavouring, I notice, the inside and the outside (7)
I believe the answer is:
aniseed
'flavouring' is the definition.
(I've seen this before)
'i notice the inside and the outside' is the wordplay.
'notice' becomes 'see' (notice can mean to spot or see).
'the inside' means one lot of letters goes inside another.
'the outside' indicates putting letters inside.
'see' put within 'and' is 'anseed'.
'i' put into 'anseed' is 'ANISEED'.
(Other definitions for aniseed that I've seen before include "Flavouring of sambuca" , "Strong herbal flavouring" , "Flavouring herb" , "Strong flavour" , "Liquorice flavouring, used in cookery" .)