Love new filling cooked in oil vessel (10)
I believe the answer is:
friendship
'love' is the definition.
(thesaurus)
'new filling cooked in oil vessel' is the wordplay.
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'filling' means one lot of letters goes inside another.
'cooked in oil' becomes 'fried' (I've seen this before).
'vessel' becomes 'ship' (ship is a kind of vessel).
'n' placed within 'fried' is 'friend'.
'friend'+'ship'='FRIENDSHIP'
(Other definitions for friendship that I've seen before include "camaraderie" , "Relation between mates" , "Amity" .)