I've been considering this thread for some time... Do you need to consider what is behind your target (pot/food)? You just may have the making of an inexpensive energy weapon. It reminds me of a larger version of the magnifying glass we used as kids to burn insects. This is just pointed up rather than down, although I guess you can point it anywhere as long as you can get a reflection from the sun.
I just wouldn't want to read about a fire started on a neighbor's house because it happened to be right behind your dinner.
