I believe I’ve found out two methods to answer my question … corrections gladly accepted :
1) Setup a new project > Premier Pro > Preferences (on a Mac)> Audio
in the Source Channel Mapping area/ Audio Channels, choose Mono from the Default Track Format drop down menu > OK
Now when ever you pull a video clip with stereo audio track, or a stereo audio track, onto the timeline, the
audio tracks automatically show up as two mono tracks on the timeline.
2) Select a video with stereo audio file or a stereo audio file in the Project Panel > Clip > Audio Options > Breakout To Mono
Now the video/audio files shows up with xyz.mov Left & xyz.mov Right underneath the original file in the Project Panel
Pull two broken apart mono tracks onto timeline.
Pages 215, 216 Premier Pro user manual CS 5.5