Famous actor, one found in more demanding title role? (7)
I believe the answer is:
olivier
'famous actor' is the definition.
(I've seen this before)
'one found in more demanding title role?' is the wordplay.
'one found' becomes 'i' (I've seen this in other clues).
'in' means one lot of letters goes inside another.
'more demanding title role?' becomes 'oliver' (Dickens' Oliver Twist asked for more food).
'i' placed inside 'oliver' is 'OLIVIER'.
(Other definitions for olivier that I've seen before include "English actor best known for his Shakespearean roles" , "ham? Definitely not!" , "Former acting lord" , "N Messiaen, French composer" , "Noted actor" .)