Solar Ovens work by collecting and focusing sun light. Here is a simple diagram. of one style.

Some dispense with the transparent cover and simple collect and focus the light.

You can even make one out of a cardboard box and foil.

That last one is one I made some excellent enchiladas in during a camping trip.

Here is one that works great on a boat and is easy to transport.

They all share the same principal. Collect and focus the sunlight.

8 Best Solar Ovens

Based on dozens of customer reviews and ratings, the followings are the top 8 best-selling Solar Ovens: