It can be done with a fire, but it is very tricky. If it is not done properly you will burst a lot of stone making it useless. An oven will work, but you are heating a lot of extra space. The easiest, & most affordable way I know is with an electric Turkey roaster. Since moving into town that's the method I use. I prefer a fire pit, but its just not doable. The roaster is quick,simple ,& works great. The only downfall I know of is they only go to 450 to 500 degrees. Tower