Love my solar cooker, the combination of that and solar hot water tank has reduced our gas consumption from a bottle every 3 weeks to one every 3 months - and probably extended Mr Clara´s life as he has to carry them 1km over a mountain path!
If you can get to boiling point (or even just below) they are a good way of cooking slow items such as pulses and casseroles, and because you are likely to be cooking at reduced temperatures, the nutrients in the food will be less likely to be lost - sorry evangelising now
Solar Honey Cake (even if you don´t have a solar oven, really yummy and contains no sugar)
Heat 1/3pt honey and 1oz butter until butter is melted
Off the heat add 6oz wholemeal flour, pinch of salt, 1 teaspoon ginger, 1/4 tsp nutmeg, 1 teaspoon cinnamon and 1egg. Beat.
Blend 3/4 tsp bicarb and 3tbsp milk and then add to the mix.
Turn into 9¨greased sandwich tin.
Bake at 160C for 25-30 minutes (though this alters with altitude and temp of solar cooker).