Matcha

Matcha runs macOS in a proxmox VM with an OpenCore BIOS that contains an SMBIOS setup for iMacPro1,1 which matches my AMD Ryzen 9 3900X 12-core processor well enough.

Installation

You can follow thenickdude's awesome guide with these secret sauce bits to get going. I'll add some notes since those might disappear...

Note that thenickdude's Monterey install wasn't working on July 3 2022, as it was pulling the wrong image from Apple. I used Big Sur and once running, immediately upgraded it to Monterey, which went flawlessly.
Set up a OpenCore VM with an unclaimed serial using SMBIOS iMacPro1,1 to match up well enough with my AMD Ryzen 9 3900X.
This helped to mount and access the EFI boot drive.
I used a macOS release of my old fave Meld

See here for more info:

💉 m@cast  [~/apps/macOs-on-proxmox] 
# ^ see readme.txt and install.sh
matcha HOME / apps
EFI Agent > icon in toolbar > EFI drive > mount > browse to OC > config.plist