What can I delete from UEFI boot partition?

Bought a new machine, a fanless server type, and I have installed Arch Linux successfully. It boots, runs daemons, etc.

The machine came with a (probably pirated) copy of Windows installed. What can I delete from the /boot directory (which is what /dev/sda1 is mounted on)? I’m never going to boot Windows on this machine again, I’ve already overwritten it.

There’s a bunch of files under /boot/Boot/ that look like unnecessarily fancy Windows bootloader things, fonts, “resources”, memtest.exe. There’s also a directory /boot/EFI/Microsoft/ that looks totally extraneous for a Linux machine. Can I delete all of those files?