I'd love to do primitive cooking like that, but it appears to be more suited to large volumes, so I've never been able to justify it to myself. Funny thing is that I have the concrete blocks and metal raw materials already in some of mu junk piles on the property.
I have only seen a variation of this once when I was in Groton, CT., believe it or not on a beach in that area where I was invited. They dug a huge hole in the sand and began burning logs of wood and charcoal until they were pretty well burned down. Then they covered the whole thing with sea weed and put on a couple of bushels of corn, potatoes, more seaweed and about 100 lobsters and a couple bushels of clams. Covered all of that with seaweed again and uncovered everything in a couple or three hours. Pretty tasty stuff naturally salted by the ocean and the seaweed. The kegs of beer provided a nice finishing touch. Similar concept. Good food.
Ed
That reminds me of our wedding where my wife found Hawaiian caterers that claimed they could do kalua pig (cooking pig in the hole). I heard that they dug the hole, built a fire and let it go to coals, then piled in banana leaves, the pig, covered, and then buried with the dirt.
Although I was too busy to take pictures (imagine that), a friend who was the photographer was not really in to food, so these are the only shots we have of the process. However, I ate the pork and it was among the most tender I have ever had. I wish I had better pics
Very friendly chaps
The unveiling
You can see a bit of the pig here - I did not see it, but the story goes that it was so tender the head fell off during transportation to the table