The term “sous vide” is French for “in a vacuum”. This is a technique that involves cooking foods under pressure in vacuum sealed plastic packages (a.k.a. cryovac packages) at low temperatures, for a very long time. Sous vide cooking concentrates flavor, and changes texture. For now, it’s not available to home cooks. Even professional kitchens have had trouble because it requires expensive special equipment and guidelines to assure that the long, slow cooking will produce a safe product.
Here’s an article that explains further, from the NY Times.
cryovac or sous vide