There is, the French say, black gold in Virginia (5)
I believe the answer is:
voila
'there is the french' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.
'black gold in virginia' is the wordplay.
'black gold' becomes 'oil' (I've seen this before).
'in' is an insertion indicator.
'virginia' becomes 'va' (US state abbreviation).
'oil' put within 'va' is 'VOILA'.
'say' is the link.
Can you help me to learn more?
(Other definitions for voila that I've seen before include "See there, behold - in France" , "French interjection - there you are!" , "The French see" , "Announcement from French producer" , "There you go!" .)