Last week at Marea, a New York haunt of the powerful and the polished, Lauren DeSteno moved up from executive sous-chef to chef de cuisine. It may sound like a mere tweak of a title, but in a small way it is revolutionary.

The promotion puts her in charge of one of the highest-earning kitchens in New York, where four male sous-chefs and 20 other cooks report to her. And though previous generations of female chefs had to fight past widespread sexism and a locker-room work culture to reach the top, at 31 Ms. DeSteno is calm, confident and entirely unsurprised by her success.

“In a good kitchen,” she said (and she has worked at some bad ones), “male and female really doesn’t matter anymore. You get the work done, you handle yourself professionally — because kitchens can still be crazy places — and you go home.”

Ms. DeSteno is living an idea whose time may have finally come: that one’s sex has nothing to do with the real work of a chef. In baby steps, the American restaurant kitchen, a high-pressure arena that still bears the image of the tough-talking, pot-throwing male cook, is beginning to reflect that idea, especially in the places where the most promising young chefs try to get a foot in the door.