Flavouring ingredient the writer's upheld in article (5)
I believe the answer is:
thyme
'flavouring ingredient' is the definition.
'thyme' can be an answer for 'ingredient' (thyme is a kind of ingredient). I'm not certain of the 'flavouring' bit.
'writer's upheld in article' is the wordplay.
'writer's' becomes 'my' (belonging to the person who set the crossword).
'upheld' says the letters should be written backwards.
'in' is an insertion indicator.
'article' becomes 'the' (the definite article in English).
'my' backwards is 'ym'.
'ym' placed inside 'the' is 'THYME'.
'the' is the link.
Can you help me to learn more?
(Other definitions for thyme that I've seen before include "Small shrub: leaves used to season food" , "Sweet-smelling herb of the mint family" , "Seasoning plant" , "Strong-scented herb" , "Kind of mint" .)