AFAIK there is only one way. Follow the instructions after selecting "Restore from Time Machine" in Recovery.
Time Machine backups in Big Sur are Data volume only so it will lead you to reinstalling the System Volume by download and migrating from the TM backup you select.
You do have a choice of doing the migration with Setup Assistant at the end of the install, or doing the migration later with Migration Assistant from the Utilities folder. I have only tested the Setup Assistant way.
There is no “best way”. Migration assistant is arguably the most convenient. But you can also just manually copy over what you need. Depends on your situation.