Sure, you know you need to be mobile; rule number #1 is cardio, after all. But since we all know Twinkies don't actually last forever, how will you feed yourself as the zombie war wages on? Prepare for long haul by pulling out the craziest, most resourceful cooking tricks you can muster! These methods might seem impractical now, but they could come in handy when our modern lifestyles decay into post-apocalyptic debris. Plus, even if you're on the brink of extinction, you can still treat yourself to something tasty, right?
Portable solar ovens
Solar ovens are extremely portable and can be made out of almost anything, as long as you've got mirrored surfaces. You can even make one with an old pizza box, a little cling wrap, glue, and tape. The foil reflects sunlight onto the item cooking in the box, and the insulated heat cooks the food through. Cooking with mirrors could be a useful trick, with materials fairly easy to come by in post-apocalyptic America.
Flash Cooking with a fresnel lenses
A fresnel lens is a plastic lens that is smooth on one side and ridged on the other; it is designed to have the same magnifying effects as a typical magnifying glass, but portable and lightweight. You could start fires with it, use it as a weapon, or cook your food! Some vans have these as lenses for rear windows. It might be a good thing to pry off an abandoned vehicle or two while you hit the road.
This will likely only be useful at the onset of the apocalypse, if you prefer to keep a home base and stay low to the ground. As Bob Blumer demonstrated in "The Surreal Gourmet," fish (specifically salmon) cooks at almost the precise time and temperature that most dishwashers wash dishes. Just wrap your fish in some foil and set the dishwasher to "cool dry" ("pots and pans settings are overkill"), and you should be all set (for as long as your gas and water keep running, anyway.)
If you're one of those folks getting out of town while there's still gas to get with, you can cook food at the same time! Engine block cooking works essentially the same way as braising or slow cooking. Just wrap up your food in foil and put it in an engine hot spot, and it'll cook as you drive. Cooking times are a little faster than your average crock pot, but you'll probably have plenty of other things to occupy your time as you wait.
Cooking with Volcanoes
Cooking with geothermal heat might be useful if you're on the move and happen to spy an angry volcano. You'll need some time, but if you're setting up camp anyway, you can dig a hole near a volcano and bury your food in the ground, allowing residual heat to slow-cook it, or you can coat your wrapped up food in hot lava and crack the hardened rock lava off after its cooled.
Instant Frozen Food with Liquid Nitrogen
If you happen across some source of liquid nitrogen, you can treat yourself to some instant ice cream on the move. (The ability to freeze things could also come in handy if that belief that zombies dislike the cold is true). Pouring liquid nitrogen slowly into your ice cream, and stirring, causes the mixture to freeze in just a few minutes.
Cooking with Ultrasonic Waves
If you can manage to raid a dentists office or a jewelery store, use can use their ultrasonic tools to cook foods! Research chefs in Bellvue, Washington used intense ultrasonic sound waves to cook up a heaping plate of delicious fries with a lengthy ultrasound treatment at 40 kilohertz. This is probably the least practical method for overall survival, but when else would you ever get to do something like this?
In a compost pile, the heat energy created as bacteria convert composted materials can actually get hot enough cook with; industrious environmentalists have even cooked whole turkeys this way! Since your entire world at this point is probably filled with compost, it could be a useful strategy. Plus, the stench might help cover your scent, and who's going to think to find you squatting by a pile of hot garbage?
Photo Credits: Solar Passion, Romantic Ruins, Kitchen Pantry Scientist, Green Power Science, Rachel Ray Mag, SF Gate, Infotainment News, CenBlog, Scientific American, Aroid