A new suggestion regarding opening course (9)
I believe the answer is:
antipasto
'opening course' is the definition.
(type of appetizer in Italian cooking)
'a new suggestion regarding' is the wordplay.
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'suggestion' becomes 'tip' (tip is a kind of suggestion).
'regarding' becomes 'as to' (as to that topic...).
'a'+'n'+'tip'+'asto'='ANTIPASTO'
(Other definitions for antipasto that I've seen before include "course of hors d'oeuvres" , "what to eat first" , "Starter course in an Italian meal" , "course leader" , "Appetizer course in an Italian meal" .)