If you’ve never seen a Swedish fire torch, it’s essentially using a single, split log to make and contain a fire for cooking, heating water, etc. This video by Reggie Johnson is a great demonstration on how to make one, which is a very straight-forward process.
Essentially, you just split a log using a hatchet into 4 split pieces. You then piece the log back together standing on end, pack some kindling into the middle of it and start a fire. The fire will exit the top between the split pieces. You can easily move the pieces to adjust the airflow into your Swedish fire torch to adjust the flame.
Once the fire is established, just set your pot of water or whatever you are cooking on top, and wait for it to cook, boil, etc. – It’s that simple. Once your done, just pour a bit of water on the Swedish fire stove and your done since the fire is well contained within the single, split log.