Leaves in arrogant fashion (8)
I believe the answer is:
tarragon
'leaves' is the definition.
(I've seen this before)
'arrogant fashion' is the wordplay.
'fashion' is an anagram indicator.
'arrogant' is an anagram of 'TARRAGON'.
'in' is the link.
(Other definitions for tarragon that I've seen before include "leaves" , "Strangely arrogant herb" , "seasoning" , "Arrogant sort of herb" , "cooks may use it" .)