• Depuis une debian live :

# apt update && apt install lvm2 cryptsetup
# cryptsetup luksOpen /dev/sda2 home
# mount /dev/mapper/vgname-lvname /mnt
# mount /dev/sda1 /mnt/boot
# mount /dev/sda3 /mnt/boot/efi
# mount -o bind /proc /mnt/proc
# mount -o bind /sys /mnt/sys
# mount -o bind /dev /mnt/dev
# chroot /mnt /bin/bash
# grub-install --target=x86_64-efi --efi-directory=/boot/efi /dev/sda
# update-grub2