As CIHY mentioned, tha pasta is rarely leftover. If you get lucky the crew might have one going spare but the chances are they won’t. Even if they do there’s no guarantees this can be released to WT+ as leftover Club meals make up the Cabin Crew’s meal allocation for the flight. As mentioned, the easiest way is to order a VL or VG meal which will be the same as that given for a Club passenger.