[CentOS] Display boot menu with GRUB_TIMEOUT=0?

Hi,

On my minimal installation of CentOS 7, here's what I have in /etc/default/grub:

GRUB_TIMEOUT=0 GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)" GRUB_DEFAULT=saved GRUB_DISABLE_SUBMENU=true GRUB_TERMINAL_OUTPUT="console" GRUB_CMDLINE_LINUX="rd.lvm.lv=centos_amandine/root \ rd.lvm.lv=centos_amandine/swap \ video=1024x768 \ quiet" GRUB_DISABLE_RECOVERY="true"

According to the official documentation, pressing any alphanumerical key just after the BIOS screen will make the GRUB menu appear. I tried that, but to no avail.

Any idea what's the magic combination to make the GRUB boot menu appear when GRUB_TIMEOUT is set to 0?

Cheers,

Niki