When plebes like you and me try to steam food, it's an inexact and often sloppy exercise. Wylie Dufresne of wd~50? He uses the Winston CVap, which is a hulking box that uses steam and evaporation for precision cooking.
Wylie does a pretty good job of explaining just how the CVap works in the above video, but here's the description from the product's site to lay it all out for you:
Winston equipment uses CVap technology to independently control the temperature of the water in the evaporator and the temperature of the air in the cabinet. Since food is mostly comprised of water, controlling food quality is dependent upon control of food moisture. The oven controls evaporation by producing a vapor-laden environment that completely surrounds food with moisture, creating an opposing vapor pressure that prevents the food from losing or gaining too much moisture. Independent control of air temperature determines the texture (browning level or crispness) of your food product. Independent control of water temperature matches the vapor temperature of the cabinet with that of the food being cooked or held, thus creating an ideal environment for maintaining food temperature over extended time periods.
Wylie uses the CVap to make dishes such as turbot, barbecued lentils, cauliflower and dried apricot. He cooks both the turbot and the cauliflower in the CVap, albeit at different temperatures, to perfectly cook the fish as well as turn thinly sliced cauliflower into cauliflower chips. Mmmm, delicious.
Basically, if Dan replaced his dishwasher with one of these, he'd never fail at cooking a piece of fish again. It's able to stop cooking when it senses something is done and just hold food at temperature, which is surely a godsend for chefs who are trying to keep their eye on a half-dozen things at once. Basically, this is something that most amateur cooks would love to have on-hand, but it's just a bit too specific for a regular kitchen. But for a pro like Wylie, he can use it to cook proteins and vegetables alike in a way that you never could do at home, and expend less effort while doing so. Hell, it'd probably be even more useful for talentless schlubs like us, but I guess that's just the way life is. [Winston CVap]