Eating lunch with Ruth Reichl at a New York City sushi restaurant, you can see right off why she's so good at what she does. When the former food critic for The New York Times and current editor of Gourmet magazine confronts a bowl of soup, she takes her time inhaling the aroma and contemplating the arrangement of ground shrimp and mushroom with eel on top. When she finally digs in she practically jumps up and down. "I love this," she exclaims. "This is so good." Sure, she can write; sure, sure she knows about food. But what finally distinguishes her response is the passion she brings to the table.

And now that she's no longer a restaurant reviewer, she can leave her wigs at home. At the Times, as she recalls in her beguiling new memoir "Garlic and Sapphires," if she made a reservation in her own name, the steaks got thicker, the raspberries bigger and the service downright obsequious. To find out how an ordinary diner fared, she had to impersonate one. Tucking her extravagant hair under a wig and wearing a shopworn beige Armani suit, she became Molly, an ex-schoolteacher from Michigan, and got the goods on a lot of pretentious restaurants. Over the years, the disguises multiplied--at one point, she even dressed up as her own mother. "It is so nice to go to a restaurant now," she says. "I get to gleefully be myself."

Sometimes "Garlic and Sapphires" reads like "The Three Faces of Eve" with recipes: Reichl worried that she was losing any sense of who she really was. And she wondered, as she put it over lunch: "Did I really want my tombstone to read, 'She told people where to go to eat'?" When the Gourmet job came along in 1999, she jumped at it: here was a chance to take on the whole culture of food. "How and what we eat is important," she says. "And eating together is one of the things that holds a society together." She laughs. "This is me at my most horribly earnest. But all those things do matter deeply. Does it matter deeply where someone goes out to eat tonight? Probably not." Food critic, social critic, dietitian and literary stylist, Reichl is much more than the sum of her disguises. And she sure knows how to clean her plate.