How can I burn an OS X Lion install DVD once the installer has been auto-deleted?

Question

I've just installed OS X Lion on my iMac, and I want to make an installation DVD, so that I can reinstall without having to first install Snow Leopard.

The way to create the DVD is answered elsewhere, but it seems that the installer gets auto deleted after the installation of Lion completes.

It looks like I'll have to re-download the 4Gb Lion installer again, but when I try to download it again via the App store, I'm told a newer version already exists, and I'll have to move it to the trash first.

I've double checked, and there isn't another version of the installer present.

How can I now create the install disk?