A traditional clay oven.
image by http://www.cs.cmu.edu/~srinivas/final/clay_oven_result2.jpg
Clay fireplaces are traditionally used like ovens. Called hornos in Spanish, clay fireplaces are still used in many rural areas of Mexico and the American Southwest. Always use a clay fireplace outdoors in a firesafe area. To cook food in a clay fireplace, first build a fire inside the structure. When it gets hot enough, rake the fire out. Place bread, or another food item, inside the fireplace and seal it so the food can bake.
Select a clear, fireproof patch of ground. Clear away all debris anywhere near the spot.
Pack down the earth in an area that's about 5 feet square. Draw a circle on the earth that is 3 feet in diameter.
Construct a latticework dome 3 feet in diameter using your lathes (or canes). The dome should be as high as it is wide, and should resemble the upper half of a globe. To form the dome, bend the lathes into an arch-like shape. Go in one direction first, then lay another section of lathes on top (and perpendicular to) the first layer. You will end up with a loose crisscross arrangement of lathes with several inches of space between each lathe.
Build an arched tunnel that's 2 by 2 feet out from one part of the dome. Use the same method of construction as you did for the dome. Remember that the lathes do not need to be tightly interlaced.
Cover the entire structure with clay that's at least 8 inches thick. Allow the clay to dry completely. Close the door to the tunnel with a large stone or iron plate. Remove this door when building or raking out the fire inside your clay fireplace.