Two bowls, one in plastic or hardened glass for water, and one in stainless steel or cast iron for water. The water in the upper bowl works as a magnifying glass onto the water in the lower bowl, bringing it to a boil as soon as the sun shines.
With a stand of separate metal rods to keep the upper bowl positioned above the lower bowl, and the lower bowl having a flat bottom, no other parts are needed to cook a nice soup or boil some veggies, and by keeping the metal rods detachable, the whole set is easy to put away in a backpack or in the kitchen cupboard after use.
(Note: changed the name from Sun Chef to Cooked Sun after I looked around on the Internet and found another type of invention using this name. Sorry for any confusion ocurring there!)