How Do I Restore Time Machine Backup From High Sierra To Mojave On iMac?

I recently backed up my iMac high Sierra to TM. I want to upgrade to Mojave. I prefer to do a clean install from bootup drive. My iMac 2013 has been sluggish and this will be my first clean install (I could just upgrade w/o clean install?). I then want to restore from TM. What’s the best option, to both retain a clean install with restored files? Restore from TM Backup or migration assistant or??
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Ed