Resolved on returning notes (3,2)
I believe the answer is:
set on
'resolved' is the definition.
Although both the answer and definition are verbs, they are not in the same form of the verb.
'returning notes' is the wordplay.
'returning' says the letters should be written in reverse.
'notes' reversed gives 'SET ON'.
'on' is the link.
Can you help me to learn more?
(Other definitions for set on that I've seen before include "Determined" , "Attack" , "Go" .)