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' says the answer is hidden in the clue.
'CELEB' is hidden in the letters of 'essence le bon'.
'is a' is the link.
(Other definitions for celeb that I've seen before include "Prominent figure" , "Famous person (colloq.)" , ""Personality"" , "popular star" , "Household name" .)