Gas cooking (oven and stove) is the cheapest alternative when you are going off grid. Many people also use cast iron ovens (like Argers) and cook with firewood.
The truth is, if your off the grid system has been set up correctly according to your needs, then you should be able to use any modern appliance – just like you did when you were ‘on the grid’. So grills, ovens, stove tops, stand-alone pans, food processors, blenders, and even the increasingly popular Thermomix will work on your off the grid system.
On special occasions or when the weather permits some people with a penchant for cooking outside use BBQ’s, run on either gas or firewood. Others use fire pits, outdoor pizza ovens, and the portable solar oven has become popular over the last few years.