Big cheese sandwich on cholesterol-packed wraps (6)
I believe the answer is:
Here is my best explanation:
'big cheese' is the definition.
'sandwich on cholesterol-packed wraps' is the subsidiary indication.
'wraps' says the answer is hidden in the clue (wrap can mean cover or conceal).
'honcho' is hidden in the letters of 'sandwich on cholesterol packed'.
(Other definitions for honcho that I've seen before include "leader", "governor" and "Leader (US slang)".)