Install grub 2 on a UEFI system, EFI partition, on Arch Linux
Commands:
sudo pacman -S grub efibootmgr
sudo mount /dev/sdxx /mnt # sdxx is your EFI partition.
sudo grub-install --target=x86_64-efi --efi-directory=/mnt --bootloader-id=grub --recheck
sudo grub-mkconfig -o /boot/grub/grub.cfg
sudo grub-mkconfig -o /mnt/EFI/grub/grub.cfg
* Note: If you got an error, try this before grub-install:
sudo mount /dev/sdxx /boot/efi/
sudo mount -t efivarfs efivarfs /sys/firmware/efi/efivars/