@davistran86 this worked excellently.

i adopted mine to http flawless

@george1421

Thanks for that - I’ve got it booting - my menu entry now looks like:

Menu Item: fog.ubuntu-server
Description: Ubuntu Server 16.04
kernel tftp://192.168.0.22/os/ubuntu/16.04/server/vmlinuz
initrd tftp://192.168.0.22/os/ubuntu/16.04/server/initrd.gz
imgargs vmlinuz initrd=initrd.gz root=/dev/nfs netboot=nfs nfsroot=192.168.0.22:/images/os/ubuntu/16.04/server/ locale=en_GB.UTF-8 keyboard-configuration/layoutcode=gb
boot || goto MENU

Many thanks again for your help!