How do I create a "platform" and "site" from CLI, using the drush extension provision I'm trying to figure out how to use Provision to create new sites from the CLI.

I tried looking at what commands Aegir normally passes to Provision when setting up a new platform and then a new site on that platform, but I haven't succesfully made it work from CLI.
There is a good article on this question in Aegir official documentation here:
http://community.aegirproject.org/content/manage-your-aegir-system-command-line