i saw 2 diffrent way of baking in the field this weekend.
One of them was using 2 set of campingstyle pots and lids. You take a large pot and put the lid of the smaller pot in the larger pot first to act like a spacer ( for airspacing ). This way your food won't burn to the botom. than put the food in to the smaller pot and put thay in to the larger pot, on top of the small lid. Leaving airspace between the pods. Than put the big lid on to the large pot and put it in to the fire.

way number 2 is to dig a hole, make a fire, and add rocks to the fire to heat them. Than wrap you'r food in leaves. Put you wrapped food in to the fire and quickly cover it. If that isn't done it time the leaves will burn through. This can also be done with a large pod, where you add the coals of your fire and heater rocks. ( is the large pot in the picture )