How do I bake bread without an oven?

Many years ago, we made a cardboard box oven at camp. It lasted almost a year of at least monthly use. At least one weekend a month, we deployed it. We baked desserts to huge roasts in it.

We used the largest, heaviest weight cardboad box we could find. Think it was something like 30" x 30" or so. We lined the inside with aluminun foil. The tip here is to use Elmers glue as it can handle the heat and is not toxic. We cut little slits on the sides to run bars through for the inside rack. Tip here was I drilled holes in them and put paper clips to keep them from going through. By the way, everything was done with Swiss army knives and/or multitools. We did three layers. We added the bottom one right above the burner so we could add a steel plate as a heat diffuser. We then cut a small circle on the botton and cut an X through it. This is where we inserted a cheapie coleman burner.

Finishing touches. Since were were using a small propane canister, the box had to be raised. I found an old folding camp chair that someone had thrown away. So I reclaimed it. Removed the fabric and adjusted it to fit the box, then tied it to retain the position. This gave us enough clearance to thread in the propane underneath. And gave us a more comfortable working height. It is a top loading oven as configured. Structurally more sound that way. Then we got a thermometer and punched a hole in the side to stick it in. We were able to get very accurate with our temperatures. Last thing was a large metal plate was used only when we made the roast since it was in there for something like six hours. The plate went over the top to keep the flaps closed to retain heat. For most other stuff, we just closed the cardboard flaps. Remember, the flaps need foil too.

It survived heavy rain. At least the splatter as we kept it under cover as much as posible. And after a year, we had a small burn because there was a little tear in the foil. Easily repairable. But we chose to give it an honorable retirement.