He's got another video showing how to set up an earthen oven that's useable sooner, but not as durable. It's the sort of oven an encamped army would set up if they were going to be in one spot for a moderate length of time.
His whole channel is excellent. I've cooked a few of the recipes he's shown. He did some really excellent asparagus side dishes, beef pasty and an awesome pork pie.
What I like about him is he's not one of those fanatical foodies. He doesn't insist you use a real wood-fired stove, 18th century cooking implements or expensive hard-to-find ingredients. The pork pie recipe called for gelatin made from boiling pigs' feet, but he said "if you don't like that idea, just use some packets of unflavored gelatin prepared according to their instructions." Most people with YouTube cooking channel would freak out at the idea of using canned ingredients as opposed to fresh.