I found this on HappyNews.nl. (Dutch site)
In the Argentinian town of La Puna, one of the sunniest places in the world, you see solar stalls more and more these days, food stalls where people cook on nothing but solar heat.
During the carnival festivities in the northern area Lap Puna solar stalls pop up, in Tilcara, Humahuaca, La Quiaca, Purmamarca and Uquía, all of them tourist spots.
The solar cooker (kiosko solar) is a cart on wheels which has a mobile solar furnace, nothing more than a strip of pleated aluminium with a diameter of 1.20 metres / 4ft. In the centre of the strip they mounted elements on which the cooking is done.
"People don't believe that this works, and when they try it they're surprised," says Marta Rojas, a teacher who started a solar cooker in Tilcara. "They want to touch the strip and then they get burnt," she laughs. On her cooker she prepares pizzas and quinopastries.
More information on solarcooking on wikipedia (in English).