First question would be ..... What is it that you are trying to record in stereo?
When you record a stereo track, you normally would be recording two channels of material (ie Left and Right) containing different material (or maybe slightly different .... think stereo image).
If you are recording ...say just a guitar track with no stereo effects (stereo delay or what not) ... you will only have the one output of the guitar material (no form of stereo image). That single audio signal would normally be recorded to a mono track and panned accordingly in the mix. No need to send one signal to a stereo track, as that would be a larger file size and be the same thing as having a mono track panned center.
You can, however, expand a mono track to stereo if you are wanting to use some form of stereo effect (plugin) on that track.
In essence, if you are trying to capture a true stereo image .... yes you need to use two inputs for the stereo track, or as has been said .... use two mono tracks and pan accordingly.
HTH