I am always searching the ‘net looking for good, cheap, inexpensive, easy ways to DIY, these sites are right up my alley, I thought you might like them too. The first one is how to make a hay box cooker with more modern (and sanitary) materials:
The second one is how to make a minimum solar box cooker:
Just don’t try to combine the two, it’s not safe to use the materials used in that hay box cooker in a solar oven, the temps get way too hot and the materials used in the hay box cooker would off gas potentially toxic gasses, would probably make your food taste bad and might make you sick.
Wretha