GI Mario sorted out paperwork? (7)
I believe the answer is:
origami
'paperwork?' is the definition.
(artworks made from paper)
'gi mario sorted out' is the wordplay.
'sorted out' indicates anagramming the letters.
'gi'+'mario'='gimario'
'gimario' is an anagram of 'ORIGAMI'.
(Other definitions for origami that I've seen before include "folding process" , "that's folding" , "The folding of sheets" , "Creation of objects from paper" , "Eastern art" .)