This is the inspiration for the solar oven Harley uses in Growing Home. In the story he also has a solar cooker that focuses sun on the bottom of a cooking pot, enabling him to boil water and fry food.
This solar oven has seen a lot of service, having traveled twice to Baja where it cooked our beans, rice, cookies and potatoes to perfection in a fuel scarce area. At home we use it about once a week to cook beans or rice. When the reflectors are angled correctly and it is a sunny summer day, the cooker can be oriented ahead of the sun so that it "turns itself on and off" as the sun moves through the sky during the day. Then we can come home to a warm meal waiting in the oven. In the winter, with the sun at a lower angle, we need to turn the cooker to follow the sun a couple of times while the food is cooking. It is impossible to burn anything in the oven because there is no "hot spot". At worst, food can dry out if left too long.
Our original solar oven was inspired by one in Beth and Dan Halacy's book The Solar Cookery Book publ. in 1978. Gerry made some modifications as he made his first oven. Since then he has continued to experiment, using different insulation materials (the latest used wool) and trying to find the best materials and method of attachment for the relectors.
Please feel free to use the directions he drew up as an inspiration to experiment with making a solar oven of your own.