Chewy stuff made from corn for grinding on sides of ledge (7)
I believe the answer is:
gristle
'chewy stuff' is the definition.
(chewy parts of meat)
'corn for grinding on sides of ledge' is the wordplay.
'corn for grinding' becomes 'grist' (I've seen this before).
'on sides of' suggests removing the centre.
'ledge' with its centre taken out is 'le'.
'grist'+'le'='GRISTLE'
'made from' acts as a link.
(Other definitions for gristle that I've seen before include "Stir leg (anag.)" , "Glister with animal tissue" , "Sinew" , "Chewy cartilage" , "Cartilage in meat" .)