If you grew up in the 70's, you'd likely remember Crock Pots. These were a slow cooker device that cooked meals over long periods at low temperatures. You could create mouth watering stews and use a fraction of the energy using a slow cooker - fire it up in the morning before you go to work and it's ready when you come home.

Aside from the energy saving attributes of slow cooking, it can also take cheap, tough cuts of meat and make them very tender. In fact, tougher cuts will turn out better in a slow cooker than expensive, tender cuts will .

A hotbox takes things one step further by reducing the need to have energy continually applied - which is also somewhat safer than leaving a slow cooker unattended.

A hotbox is basically a super-insulated container into which a pot that has been initially heated with the food within is placed. Using a hotbox you can boil rice for just a few minutes and then let the captured heat do the rest over the remainder of the day.

One of the great things about a hotbox is that it can cost you absolutely nothing to make and you don't need to be a whiz with tools to make one, they are very simple to construct. You likely have all the components you need to make a hotbox around the home - a large cardboard box and insulating material such as towels, paper or straw.

Brian Liloia over at PlanetSave has a great article on making a hotbox - check it out.

Related:

Tips for saving energy when cooking
Solar cookers