Gardenhouse the tools do things!

efivar-set

Setting efi variables from userspace without having to worry about UTF-16 conversion.

Set variable "meow" with gardenhouse uuid to value "nya":

efivar-set -e meow nya

Set variable "meow" with custom uuid to value read from file ./var:

efivar-set -e meow -u $(uuidgen) -f ./var

Source

efivar-set can be downloaded from https://git.pinkro.se/Rose/gardenhouse/efivar-set.git/about/

It's also mirrored to Codeberg where bugtracking is done.

A sys-apps/efivar-set port is available in the Gardenhouse portage overlay