Fix kernel / grub with LUKS crypted partition

gistfile1.txt

# Mounting the LUKS partition is critical, as the name that should be used should match /etc/crypttab in order
# for the rest of the toolchain to work properly

cryptsetup luksOpen /dev/nvme0n1p6 nvme0n1p6_crypt    # <-- pay attention to this (should match /etc/crypttab or update-initramfs will fail

vgchange -ay  # not sure if needed
lvscan        # not sure if needed, no output

# mount FS
mount /dev/mapper/nvme0n1p6_crypt /mnt
# mount unencrypted /boot partition
mount /dev/nvme0n1p5 /mnt/boot
# mount EFI partition. You can find its UUID in /etc/fstab, then match with blkid
mount /dev/nvme0n1p2 /mnt/boot/efi/

mount -o bind /proc /mnt/proc
mount -o bind /dev /mnt/dev
mount -o bind /sys /mnt/sys

# Chroot
chroot /mnt

# Reinstall kernel
apt install --reinstall linux-image-5.4.0-81-generic

update-grub 

exit # exit chroot

reboot