Oliver wanted this mushroom, not large (4)

I believe the answer is:

'oliver wanted this' is the definition.
('Please sir, may I have some more' - Oliver Twist)

'mushroom not large' is the wordplay.
'mushroom' becomes 'morel' (morel is a type of mushroom).
'not' suggests deleting specific letters.
'large' becomes 'L' (eg in clothes sizes).
'morel' with 'l' taken away is 'MORE'.

(Other definitions for more that I've seen before include "author" , "Greater quantity or number" , "What Oliver wanted" , "To a greater extent" , "Additional or larger amount" .)

I've seen this clue in The Times.

Want a hint initially instead of a full solution? Install my app