Herb that may be found in most of NE Spanish region (8)
I believe the answer is:
tarragon
'herb' is the definition.
(I know that tarragon is a type of herb)
'most of ne spanish region' is the wordplay.
'most of' means to remove the last letter.
'ne spanish region' becomes 'Tarragona' (region of northeast Spain).
'tarragona' with its last letter taken away is 'TARRAGON'.
'that may be found in' is the link.
(Other definitions for tarragon that I've seen before include "Arrogant (anag) - herb" , "cooking ingredient" , "Aromatic herb used in cooking" , "Culinary herb" , "seasoning" .)