Lending a hand to get a portion (7)
I believe the answer is:
helping
'a portion' is the definition.
('helping' can be a synonym of 'portion')
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for helping that I've seen before include "Giving assistance" , "Amount put on plate" , "Assisting" , "Food portion" , "Aiding" .)