To invent his thoroughly modern recipes, chef Laurent Gras looks for inspiration in his collection of nineteenth-century cookbooks.

"This is the cookbook my grandmother used back in Antibes," Laurent Gras says, brandishing a worn copy of Jean-Baptiste Reboul's La Cuisinière Provençale. "Everybody's grandmother used it in Antibes!" A best-selling cookbook in France since it was published, nearly 100 years ago, it has inspired generations of home cooks--and, it seems, at least one first-class chef.

His grandmother's legacy and the historic cookbooks of France go a long way toward explaining the rise of Gras, the 35-year-old, Provence-born chef at the Waldorf-Astoria's Peacock Alley in New York. Many chefs say they draw on the classics for inspiration, but few are as serious about it as he is. Gras began buying old cookbooks when he was in his twenties and he worked for a few months in Florence at the famed Enoteca Pinchiorri. He started with Le Ricette Regionali Italiane by Anna Gosetti della Salda, published in 1867. But his collection didn't really begin to grow until he arrived in Paris, five years ago, to develop the menu for the new restaurant Alain Ducasse.

Gras immersed himself in the old books, many of them from the nineteenth century, which he'd discover at the bookstalls lining the Seine. All the vendors knew the value of what they were selling, and the prices were pretty high. Even then, a late edition of a book by a classic author like Jules Gouffé could cost $1,000; a first edition would go for $3,000. "I was looking for tools for my profession," says Gras, "not antiques to sit in a glass cabinet. Eventually I acquired about 40 books from here and there--the bookstalls, shops, flea markets, friends. I could have bought hundreds, but I have found that a few books from each great period pretty much represent what food was like at any one time."

When he wants a new dish for his menu, Gras doesn't simply reproduce the recipes of Gouffé or other nineteenth-century chefs. Instead he studies each author's approach and then mulls it over until he figures out how to adapt it to the twenty-first-century palate. "I don't read cookbooks cover-to-cover looking for recipes," he explains. "I like to browse for 15 minutes, lay the book down and come back to it later. It may take me three months to get through one book. The ideas stay with me. Then, when I want to create a menu, I ask myself, 'What do I really feel like eating?'" Gras might combine two cauliflower recipes from the nineteenth-century gastronome Jean-Anthelme Brillat-Savarin, author of The Physiology of Taste, and a pork roast from Prosper Montagné, who published Le Grand Livre de la Cuisine in 1929 and the first edition of Larousse Gastronomique in 1938.

For Gras the process is constantly evolving. He might take a historic recipe and lay out all the ingredients, then see what new flavors and combinations he can come up with. For instance, he deconstructed a dish from Montagné for salmon with béarnaise sauce, leaving out the eggs and most of the butter. He reasoned that there's nice fattiness in the salmon itself, so he kept just the tarragon, shallots and vinegar. "The whole time," Gras says, "it's like I'm having a conversation with these old chefs who still live in these books."

The results of those conversations can be tasted in his recipes. Here are four of his most wonderful dishes.

- Peter Kaminsky is the author, most recently, of The Moon Pulled Up an Acre of Bass and coauthor, with Gray Kunz, of the forthcoming The Elements of Taste.