Something chewed includes famous sauce (7)
I believe the answer is:
custard
'sauce' is the definition.
(I've seen this before)
'something chewed includes famous' is the wordplay.
'something chewed' becomes 'cud' (I've seen this in another clue).
'includes' is an insertion indicator.
'famous' becomes 'star' (I've seen this before).
'cud' placed around 'star' is 'CUSTARD'.
(Other definitions for custard that I've seen before include "Sweet sauce made with milk and eggs" , "Pudding sauce" , "-- Pie; -- apple" , "Egg/milk bake" , "Type of apple" .)