I dont know what you mean in writing "one of those solar ovens".. I used one for years, one I made from blueprints found at the public library. I made it in 1990 out of wood, glass, metal and foil.
It took some time to make it but it was a hobby to build one.
I used it for years... BUT.. I live in deep Texas where there are only 3 seasons, warm, hot and hotter.
Mine was a box inside a box with a hinged cover.
The innner box and outer box had insulation in between the boxes. The inner box was lined with foil and had BLACK metal on the bottom to attract and retain heat.
The lid was made from an old picture frame, wood frame with glass and put on hinges.
It had a reflector built from lightweight plywood covered with foil that were removeable.. and it sat on a post that had a turntable so it could be turned into the direction of the sun.
Nothing ever burns in them...
and it takes a long time to cook.
Solar cooking was first used by the indians and the idea has been around for hundreds of years.
I made mine back in 1990 for less than 100 dollars and used it all summer, for many summers ( stored it in the shed in the winter whren not in use).
It really has to be hot out ( over 90, lots of sunshine and where I live thats 6 months out of the year) for them to work well...
and they take some tinkering with so dont start off with a expensive meal in one. Start with something easy like baking a spud.
on another note......
again, what is a heat grabber ???????