Somehow a site on our SharePoint site disappeared. We run backups, but
what is the best way to restore an individual site? Is there a way?

I was reading on the stsadm way:
The best way to backup a SharePoint site is –

Stsadm –o backup –url <SiteURL> -filename <FileName>

And then at a later date you can restore the site using

Stsadm –o restore –url <restoretoURL> -filename <filetorestorefrom>

But this would cause me to have to restore a good backup to a test
box, backup the site, then restore to the live box. Would this work?