Today, I came across a new oven under development called the Roccbox. While I haven't tried it, I wanted to share it because of how promising it looks, and also because of how useful it will probably be for members of the site.
This is a "portable" (~20kg/44lbs) high temperature oven that can be powered by both wood and gas. It'll get up to 900 degrees and heats up in 15 minutes.
Here's the site: https://www.roccbox.com/product/
Since this is a project under development, the way to purchase one is through Indiegogo, the crowdfunding site:
Again, I'm not recommending since I haven't tried it, but I did want to share it since it looks quite interesting.