I came up with this as a survival tool after Hurricane Ike. We used solar water heaters for showers and doing dishes but did most of our cooking on the camp stove. This idea came too late but as they say, better late than never.
This design works with the materials I keep in my survival kit I purchased from Outpost Outfitters which uses a solar survival blanket for the reflector but I needed a roasting pan for another project so I used it for the Instructable.
Military Mess Kit (Aluminum cooks faster but stainless steel is more durable so the choice is yours).
High Heat spray paint, black. The type used for BBQ grills.
Oven cooking bag
Reflective surface. Roasting pan was used here that I procured from a dollar store but foil or a Mylar solar survival blanket could also work just as well.
Canteen Cup Stand/stove. Use to keep the mess kit elevated so that solar radiation can reach the underside for faster and more efficient cooking. Anything you find can be used for this such as a rock or bits of broken brick or whatever you have handy. The military canteen cup stove works well as it is also aluminum and has holes throughout for good conduction. A short drinking glass turned upside down would work well too or possibly a pair of shot glasses.
Step 2: The Dirty Work
I always paint my mess kits and canteen cups using this method. It has the added benefit of reducing creosote build up from making the outside of your gear sticky and hard to clean.
First you'll need to paint your mess kit by laying it on a soft surface such as an old towel blanket. Pushing the mess kit downward to impress it into the blanket or towel keeps paint from getting on the lip of your pan and plate. You could always just use cardboard and clean off any over spray or migrating paint with steel wool after it dries. Allow the paint to set up for about 45 minutes or so and place it in direct sun to cure for about an hour. Then hit it with a second coat. Allow 24 hours for full cure before using it or follow the label instructions for drying time. Paint only the outside as you don't want your food to come into contact with the painted surfaces.
Be sure to perform this step in a well ventilated area. Paint fumes smell awful and are harmful. Kids, get an adult to help with this.
Step 3: Time to Use It.
That's it. Now lets cook with it.
Complete biscuit mix. The just add water type. This works best for camping and survival as you don't need milk.
Water. About 3/4 to 1 cup.
Soup or stew. I like beef stew but only had cream of chicken on hand.
Non-stick cooking spray or oil.
Follow package directions to mix your biscuits. Mine was adding 1/2 cup of water and stir. Simple.
Step 4: Just Add Water
Apply a good coat of cooking spray or oil to both the top and bottom of your mess kit just in case you biscuit rises enough to hit the lid. This will also make cleaning off any soup that my boil up to the lid easier.
Step 5: Assemble
Add enough prepared biscuit mix to half of the lid "plate" portion of your mess kit and spread evenly. I used a little less than half the mix. Pour roughly half the can of soup into the other half of your mess kit plate and stir in about 1/4 to 1/2 cup of water. I like mine thick so I used about 1/4 cup.
Step 6: Ready to Bake!
Carefully close up you mess kit securely using the bottom pan portion as your lid. Place it carefully into the cooking bag and seal the bag with the enclosed fastener. I like to twist the bag closed so as to make it into a balloon. The added air acts as an insulator to keep more heat inside the bag creating an oven.
Place your stand inside the middle of your reflector and place your "oven" mess kit on top of it. Put the whole thing somewhere it will get full direct sun for at least 2-3 hours.
Depending on where you live in relation to the equator and the time of year it may take up to 3 hours to thoroughly bake.
Step 7: Time to Feast
It took this meal nearly 5 hours to cook completely as I battled clouds and tree shadows. A more efficient reflector would have shortened cooking time dramatically. Just about perfect for a day hike though.
Carefully remove the oven from the reflector by pinching the top of the bag and placing it on a safe surface such as a plate or a hot pot holder. Do be sure to keep the mess kit flat to avoid spills. Be careful as this can be quite hot to the touch. Allow it to cool for a few moments and carefully pop the handle latch and open your mess kit to reveal the surprise inside. Dig in!