Cut some elephant foot yam and radish on the carving board (8)
I believe the answer is:
trencher
'board' is the definition.
(historical board used for serving food)
'cut some elephant foot' is the wordplay.
'cut' becomes 'trench' (I've seen this before).
'some elephant foot' becomes 'er' (I am not sure about this - if you are sure you should believe this answer much more).
'trench'+'er'='TRENCHER'
'yam and radish on the carving' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for trencher that I've seen before include "Plate" , "(Old) wooden platter for food" , "one at digs?" , "bearer of food" , "Board" .)