Make sure the Omega ASIO driver is selected in device setup.
In VST Connections, create a mono input bus assigned to your instrument input on the Omega.
Create a stereo output bus assigned to the L/R outputs of the Omega.
Create an audio track (mono or stereo).
Select your mono input as the track’s input.
Select stereo out as the track’s output.
Make sure the Monitor Mix knob on the Omega is set all the way to “Playback”.
Enable Record/Monitor for your audio track (you should be hearing your signal monitored from Cubase at this point).
Record your take. Disable the track’s Record/Monitor status for playback.