"Following on from haybox/thermos thread, in South Africa a charity used to promote and distribute a modern version of the haybox, called the wonderbox - which was aimed at rural African women. This can be used for cooking (rice, beans, soups, stews) and even baking. Get a cardboard box big enough to hold your cooking pot with space to spare. It's easier if the top part of the box slides over and fits tightly over the lower half. Make 2 insulating cushions using insulation material such as polystyrene. You can buy a bag of the small beads or else just grate up some used packaging. Material for cushions should be relatively heat resistant - obviously not nylon, but cotton is OK. An old pillowcase is good. Line bottom of box with 1 cushion. Now put food in pot and bring to the boil. (Can even use a solar cooker for this). Once water reaches boiling, take off the heat and nestle pot snugly in lower cushion, moulding polystyrene beads/cushion around the pot. Then place the second cushion on top and again mould snugly. Seal up the box and food will keep cooking for many hours. "