Jean-Georges Vongerichten goes foraging for his newest taste adventure.

I won't forget Jean-Georges Vongerichten's delight when he first tasted the feathery leaves of wild yarrow. The celebrated New York chef had organized a foraging trip in the Connecticut woods near my house. Before we left my driveway, we'd found half a dozen edible plants. One was yarrow.

"This is incredible stuff," he said. "It's got the sweetness of dill, but it's piercing, almost like menthol. And I taste some thyme in there; it would be perfect for shrimp." Three hours later, we were back home grilling yarrow-stuffed butterflied shrimp for a dozen overjoyed eaters. The yarrow married perfectly with minced garlic, and I swore I'd never eat shrimp with dill again, at least not in yarrow season.

Yarrow-stuffed shrimp will probably be on the menu at Vongerichten's newly opened Jean Georges in Manhattan. So will other dishes containing wild American greens, seeds, barks, herbs and roots. For now, diners who want to taste these novelties will have to go to Jean Georges to get them. If Vongerichten's past record is any indication, though, they'll soon be found in restaurants all over the country.

This isn't the first time 40-year-old Vongerichten has pursued new flavors. In 1980, he left France for Asia. "At that time," he recalls, "I had tasted little beyond the classic French herbs. Suddenly I was confronted with ginger, coconut milk, cilantro and lemongrass." After five years in Bangkok, Singapore and Hong Kong, Vongerichten moved to the States and went on to galvanize New Yorkers with his personal French-based cuisine--stark flavors, little butter, no cream, juice reductions, flavored oils and (gasp!) Asian ingredients--which synthesized East and West. Whatever he served at Vong, his French-oriented Thai restaurant, and Jo Jo, a traditional-looking bistro with markedly eclectic food, was soon championed by others.

Now he's obsessed with wild plants. "They're just as exciting as the Asian ingredients I found 17 years ago," he says. "Believe me, you have tasted nothing like yarrow or chickweed," a sweet wild green that's become the chef's favorite salad ingredient.

In the past year I've worked closely with Vongerichten on a forthcoming book, and he's always experimenting with new flavors. He has made oil with vetiver, an edible grass used almost exclusively--until now--in perfume and cosmetics. He has made chocolate candy with curry powder. He has married pumpkin seed broth with lobster, chicken breast with cloves, sweetbreads with licorice. Some of these creations are brilliant (the candy, sometimes served after meals at Vong, is a revelation; the sweetbreads are a signature dish and the lobster may become one). Some are not. But for him even failure breeds success. "I cannot know the best use for a flavor until I try it in every way that might make sense," he says.

Most of the plants he's "discovering"--including purslane, yarrow and wood sorrel--were traditionally used by Native Americans and more recently by a small contingent of nature lovers and foragers. Vongerichten, however, is not just boiling up wild edibles as part of a rustic cuisine; he is integrating entirely new flavors into established haute cuisine.

At least two chefs in France--Michel Bras and Marc Veyrat--have already gone this route, incorporating the wild plants of their regions into their cooking. Veyrat, in fact, was a shepherd until about 15 years ago, when he decided to begin experimenting with the native foods of Savoy. He literally came down from the mountains and opened what has become one of France's hottest and most controversial restaurants--Annecy's Auberge de l'Eridan, a place where wild, almost unknown ingredients share center stage with the classics of the French kitchen.

Two years ago, chef Didier Virot, who'd worked with Bras on his wild-plant cuisine, came to New York and joined Vongerichten at Jo Jo. About a year later, Vongerichten received a letter about foraging from a Frenchman named François Couplan, who'd advised both Bras and Veyrat. A world traveler, Couplan has written a dozen volumes about wild plants, including an encyclopedia.

Vongerichten immediately saw the possibilities and fired off a fax to Couplan. Within weeks, the two were traipsing through Central Park. There, in the heart of the city, Vongerichten found chickweed, purslane and 23 other edible plants, and he was hooked.

On our expedition in Connecticut, we found wood sorrel, which is stronger than garden sorrel and works beautifully in a beurre blanc­like sauce for scallops; garlic mustard, a sharp green that complements sweet wild burdock and white-fleshed fish; plantains--the greens, not the fruits--which we used to add an open, grassy flavor to a lovely gratin of potatoes; wild mint, with at least double the power of any garden mint I've ever tasted; spicebush berry, like a peppery allspice; and much more, including the ubiquitous chickweed. All in all, there was enough wild greenery for a 12-course meal of fantastic new flavors.

Now that winter is over, Couplan and Vongerichten are planning to gather enough plants to last for the coming year. (In Annecy, Veyrat collects the plants while they are in season and freeze-dries them for year-round use; Vongerichten plans to do the same at Jean Georges.)

Maybe spring will bring a new discovery. "That's the great thing about cooking," Vongerichten says. "Every time you think it's over, there's something else to play with, something new. These foods are things you step on. You don't have to travel 5,000 miles to find them, they're right under your feet."

Mark Bittman is writing a cookbook with Jean-Georges Vongerichten (to be published by Broadway Books).
Kurt Eckert, beverage director at all of Vongerichten's New York restaurants, provided the wine suggestions.