Is filling a requirement for strong flavouring? (7)
I believe the answer is:
aniseed
'strong flavouring?' is the definition.
(I've seen this before)
'is filling a requirement' is the wordplay.
'filling' indicates putting letters inside.
'requirement' becomes 'need' (synonyms).
'a'+'need'='aneed'
'is' going inside 'aneed' is 'ANISEED'.
'for' acts as a link.
(Other definitions for aniseed that I've seen before include "Liquorice-flavoured seeds" , "taste of Pernod, perhaps?" , "Strong herbal flavouring" , "Liquorice flavouring -- ie Danes (anag)" , "Plant" .)