I found few threads that explain how to reinstall grub2 by the mean of
chroot but none of them explain how to proceed if my
/ is encrypted and if there is a plain
/boot partition. Thing is I installed
Debian in EFI mode and it made an unbootable entry (Japanese character) in the UEFI boot menu.
I tried to make a new entry using
efibootmgr from Ubuntu liveUSB but it is still unbootable. I'd like to reinstall grub from Ubuntu liveUSB but I don't know to chroot the encrypted
/ partition and how the separate
/boot partition blends in.