“Cooking eggs is really a question of temperature, not time,” says This. To make the point, he switches on a small oven, sets the thermostat at 65°C, or 149°F, takes four eggs straight from the box, and unceremoniously places them inside. “I use an oven in the lab; it’s easier. But if the oven in your kitchen is not accurate, cook eggs in plenty of water, using a good thermometer.” About an hour later—timing isn’t critical, and the eggs can stay in the oven for hours or even overnight—he retrieves the first egg and carefully shells it. “The 65-degree egg!” he announces. The egg is unlike any I’ve eaten. The white is as delicately set and smooth as custard, and the yolk is still orange and soft. It’s not hard to see why l’oeuf à soixante-cinq degrés is becoming the rage with chefs in France.