Sous Vide cooking has been popular in restaurants for years.   Without getting in to the science behind it, sous vide is basically the process of sealing meats and vegetables in cryovac then cooking in a water bath that maintains a consistent temperature (set to the level of doneness you'd like to achieve) over an extended period of time in order to ensure an extremely tender, perfectly cooked end product.  

Here's more on the process of sous vide cooking as well as an amazing recipe for sous vide, then grilled, flank steak!