Comment 27 for bug 817017

Sure, I can't point out to a single website since I found out about this more or less by trial and error. The ArchWiki is a good source however.

First, I mounted my efi partition at /boot/efi. This can be achieved my using a line like this on /etc/fstab:
UUID=70D6-1701 /boot/efi vfat defaults 0 0
(substitute 70D6-1701 with the UUID of your efi partition, you can check it with "sudo blkid | grep EFI" )
(If you want to just mount it once, you can run "sudo mount /dev/sdXX /boot/efi", where /dev/sdXX is your efi partition)

Then I installed grub-efi:
sudo apt-get install grub-efi
(it will install the necessary efi components such as efibootmgr)

I think this will already install grub-efi to your drive, but if you want to make sure do a:
sudo grub-install /dev/sda

(warning, this will set grub as the primary boot option, if you have refit or refind installed, they will not run as default, to run them you'll have to hold the right-hand "alt-option" key during boot)