Cooking "Sous Vide" is a lesser known means of cooking that's been around since the 1970's. As you can tell from its name, it was invented by the French and sous vide means "in vacuum."
This technique is akin to using an oven, microwave, grill, deep-fryer, or stovetop. Each is simply a means of transferring heat to the prepared foods, while developing unique flavors and textures.
There are two major developments involved: One, food is sealed in a plastic vacuum pack. Two, the vacuum pack is submerged in water, where it slowly cooks at the desired final internal temperature.
The vacuum seal's function is many fold: it protects food from oxygenating (therefore maintaining original colour), locks in natural juices and aromas, maintains original shape, and allows excellent heat transfer. Vacuum packing is accomplished using a 'chamber sealer' - a chunky device commonly found in professional kitchens, but normally used for enhanced storage.
A special device, called a thermal immersion circulator, sits in the water bath to maintain a constant cooking temperature to a tenth of a degree Celsius. This temperature is seldom programmed over 85C (185F), whereas the typical temperature in an oven is 175C (350F). The result is a uniformly cooked food. One striking example is a thick steak, cooked to a perfectly red rare without any gray "crust" whatsoever.
This is certainly an intriguing technique with great potential. My sole concern lies in the use of plastics for cooking. We've all heard that one shouldn't microwave plastic containers, lest they may leech toxins like Bisphenal-A.