arch linux – How should the EFI partition be handled in a software raid?

I am trying to install Arch onto a computer, I have two storage devices.
I partitioned the drives identically as I would if I were installing to one storage device on efi dekstop.

sda
  sda1 (boot partition)
  sda2 (swap)
  sda3 (root)
sdb
  sdb1
  sdb2
  sdb3

I then created created an array for each partition

mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sda1 /dev/sdb1

Leaving me with 3 arrays.

md0 (boot)
md1 (swap)
md2 (root)

I then formatted each array as I would if they were single partions, i.e: mkfs.ext4 /dev/md2, mkfs.fat /dev/md0, mkswap /dev/md1. I then mounted the arrays as normal and went through the standard installation.

However, when trying to install grub to the mount point of /dev/md0, I received an error saying

efibootmgr failed to register the boot entry: Operation not permitted

I know this is misconfiguration of the boot partition, but I am unsure how the boot device should be handled in a EFI installation.