In essence, Le Bon is a star (5)
I believe the answer is:
celeb
'star' is the definition.
(I've seen this before)
'in essence le bon' is the wordplay.
'in' indicates the answer is hidden within the clue.
'CELEB' is hidden within 'essence le bon'.
'is a' acts as a link.
(Other definitions for celeb that I've seen before include "Prominent figure" , "Famous person (colloq.)" , ""Personality"" , "popular star" , "Household name" .)