One studying carefully about to call for dish (9)
I believe the answer is:
porringer
'for dish' is the definition.
(porringer is a kind of dish)
'one studying carefully about to call' is the wordplay.
'one studying carefully' becomes 'porer' (I can't explain this - if you can you should give a lot more credence to this answer).
'about' is an insertion indicator.
'to call' becomes 'ring' (telephone call).
'porer' enclosing 'ring' is 'PORRINGER'.
Can you help me to learn more?
(Other definitions for porringer that I've seen before include "Small dish" , "soup-bowl" , "Soup bowl with handle" .)