Every year about this time, a group of us get together for a solar cook-off. We all bring our solar ovens to someplace like a local park, along with any other means of alternate cooking we feel like. Most of the day is then spent cooking and experimenting with various ideas. At the end of the day we have a big meal and get to evaluate how each oven performed.
The stoves that show up include both commercial and homemade ones. Two that have been successful for my family are the Solavore (read the review here) and the well-known Sun Oven.
Some of the inexpensive homemade solar ovens work quite well, especially the large parabolic one. You can use it like a range top and even fry on it. Here’s a sampling of some of the very creative ways you can use the sun to cook food.
The all American Sun Oven is quite popular and there are always several of them present.  In the picture above you can see one cooking a roast.
The above reflector solar oven is used all the time and the friend that owns it cooks most of his meals on it.
The blackened jar in the truck windshield with the reflector behind it works well.
Solar and alternate cooking is fun and it made for a very enjoyable day with friends.
But by the end of the day we always have learned something new. This type of cooking has a learning curve, practice now before you need to. You could also pick up a copy of Cooking With Sunshine as a complete guide.
The Solar Cookers International Network is a treasure trove of just about everything you need to know about using the sun to cook food.
Here are a few links to DIY solar ovens/cookers. If you try one of these, let me know how it worked out for you.
Howard