"It is impossible to undercook or overcook this piece of meat" were the magic words from chef Jeremy Langlois during a demonstration of sous vide cooking.

Sous vide, French for "under vacuum," originated in France in the 1970s, but the technique has now caught on in the U.S., the executive chef at White Oak Plantation and Farms told those gathered there for a recent seminar. 

"Sous vide is just another method of cooking," Langlois explained. "When we cook, we use several methods of achieving certain desired effects with our food — we sauté, we deep fry, we bake, we braise. Each one of those cooking methods gives us a different result with the product that we're cooking."

Sous vide is basically cooking meat or other proteins, even vegetables, inside a vacuum-sealed bag in a bath of water brought to the desired temperature. Don't know what temperature is optimum? Just Google it, he said.

Using a thermal circulator (several brands sell for about $120 on Amazon) and the cooking vessel of choice, "set desired temperature, say 138, it heats the water up to 138 degrees and it circulates it, so this whole vessel is held within 1/10 of a degree to 138 degrees," Langlois said.

"Cooking is nothing more than controlling temperature," the chef added. 

Langlois used loin of lamb to walk participants step by step through the sous vide process.

He seasoned the coffee-marinated lamb with fresh herbs, salt and pepper, and placed it in a vacuum-sealed bag. He then dropped the bag into a container of water, with the circulator attached and set at 138 F. The lamb would be done in 45 minutes, but that's where timing flexibility comes into play. If the water is kept at a consistent 138 F, the lamb can stay in the bath for hours and not be overcooked, the chef said.

However, since the lamb will be a consistent temperature from the top to the bottom, some people might not like its appearance — the same grayish color from top to bottom, without the gradations that come with cooking over a grill or other method.

"It's not too appealing to look at, it's not caramelized on the outside, it doesn't have the little grill marks," Langlois said.

That's when you turn a skillet to high, add a little olive oil, season the lamb with another round of salt, fresh herbs and pepper, and in a minute or two you've achieved "that beautiful brown caramelization," he said.

"Once you start playing around with these ideas, it opens up so many possibilities and so many interesting ways you can go about doing this," Langlois said.

Follow Judy Bergeron on Twitter, @judybergeronbr.