Worker that's painting, say, in enthralling South America (7)
I believe the answer is:
artisan
'worker' is the definition.
(artisan is a kind of worker)
'painting say in enthralling south america' is the wordplay.
'painting say' becomes 'art' (painting is a kind of art).
'enthralling' is an insertion indicator.
'south' becomes 's' ('S' can be a synonym of 'south').
'america' becomes 'a' (common abbreviation - e.g. in organisation names).
's'+'a'='sa'
'in' placed around 'sa' is 'isan'.
'art'+'isan'='ARTISAN'
'that's' is the link.
(Other definitions for artisan that I've seen before include "Handy worker" , "Journeyman" , "Skilled worker by hand" , "Mechanic" , "Skilled workman" .)