Sauce where elegist pens verse (5)
I believe the answer is:
gravy
'sauce' is the definition.
(gravy is a kind of sauce)
'elegist pens verse' is the wordplay.
'elegist' becomes 'gray' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'pens' is an insertion indicator (to pen can mean to contain or imprison).
'verse' becomes 'v'.
'gray' placed around 'v' is 'GRAVY'.
'where' is the link.
Can you help me to learn more?
(Other definitions for gravy that I've seen before include "something saucy" , "Meat juices after cooking" , "Meat jus" , "Sauce from meat juice" , "Kind of train?" .)