This is a very easy thing to explain. First, we place the aluminum foil to the panels of the cardboard. We then put the dark materials at the bottom of the box. Next, we put insulative materials like foam, over the food. The light will bounce off of the luminous and will end up getting absorbed in the black materials. The insulative materials will trap the heat and keep all of the food warm, overall, this is a very easy and affective solar cooker to use and build.
Hear are some pictures below: it may be very big