Here are the cooking vessels I use. The jar and tin are painted with heat resistant (stove paint) flat black paint:
From left to right: A mason jar with ring and lid. These are great because they function like small pressure cookers since the lid seal gives a little and releases the pressure when it becomes too great. Be very careful though and do not handle these when they are really cooking as the lid could come loose and spray you with boiling water (I speak from experience!!).
Next is an enameled kettle. This one has a dark blue finish and works fine unpainted.
Next is an 8 inch cast iron dutch oven. Cast iron is great for solar cooking because it holds heat so well and transfers it all around the food.
Finally, is a round tin with lid and a one pound coffee can. Metal coffee cans are becoming hard to find as coffee now comes in plastic (arrgg!) so you may have to improvise. This is my bread baking outfit. The coffee can fits inside the tin without touching the sides. The dough goes in the coffee can and the tin acts as a miniature oven, getting very hot on the inside, but not touching the bread and causing it to burn. This turns out the prettiest little round loaf of bread you have ever seen!
So, if you have thought about cooking with the sun, build yourself a cooker and give it a try.