AVENUES has gone through thick and thin. When the rotund chef Graham Elliot Bowles announced his plans to leave The Peninsula’s luxurious dining room to open his namesake restaurant in River North, visions of a serious culinary void filled my head. False alarm. The new chef—lean, lanky, and amply talented Curtis Duffy—stepped into Bowles’s shoes and the highly acclaimed kitchen never missed a beat. A veteran of Alinea and Charlie Trotter’s, Duffy is like the bridge that connects two master chefs: He combines Grant Achatz’s dazzling molecular manipulation with Trotter’s exquisite nuance. And Bowles, no stranger to the cutting edge himself, gave Duffy’s hire the thumbs-up.

Achatz’s influence reveals itself immediately in Duffy’s amuse, a staggering one-bite creation that involves a Meyer lemon gêlée dome, brioche pudding, golden osetra caviar, and egg yolk drops cooked in clarified butter, among other elements. Sounds like a train wreck. It’s a wonder of harmonious flavors.

Achatz unleashed an aroma revolution six years ago at Trio when he had servers pour steaming water over rosemary before you took your first bite of roasted Maine lobster; now Duffy has taken it a step further. He bastes golden trout in spruce oil and serves it with dark green parsley purée and spruce cream with sémillon verjus and little white and brown pine-scented honshimeji mushrooms. Finished with four varieties of delicate French crystal lettuce leaves—picked at different times of the day in Michigan—the dish’s bold fragrances carry you to a forest meadow and a trout stream.

Duffy plays with molecular gastronomy in the most succulent wagyu beef I’ve ever tasted. His heavily marbled wagyu comes with its own smoky scent gained from a quick turn over Japanese charcoal; smoked coconut milk pudding and coconut milk powder ratchet up the aromatic experience even more. A cracker made of puffed tapioca pearls adds a crunchy counterpoint to the incredible richness of the beef, while yuzu vinaigrette and white shoyu/blue basil purée complete the stunning dish. Michael Muser, the sommelier, told us that the well-structured and fruity 2002 Bodegas Artadi single-vineyard Pagos Viejos Rioja he poured here enhanced the wagyu. As usual, he was spot-on.

Like Trotter and Achatz, Duffy ingeniously connects the savory courses on his tasting menus to the desserts. Recently he did it with tart citrus sorbet, grated and shaved fennel, and black olive purée set with muscavado (unrefined brown Barbados sugar) gêlée. That prepared me for a wonderful gingery carrot/white chocolate sorbet with white chocolate purée and carrot cake purée with lemongrass and passion fruit. Yes, cake purée, and it works.

Dishes like these masterfully showcase the essence of fine flavors, and they also showcase Chicago’s next culinary star. Catch Curtis Duffy at Avenues now before everyone else learns how good he is and scoring a reservation there becomes a new status symbol.

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I’ve eaten at GRAHAM ELLIOT several times now and I still have no clue what "bistronomic" means. Graham Elliot Bowles throws the term around a lot, explaining on his Web site that he’s "juxtaposing four-star cuisine with humor and accessibility." Sounds good, but he rarely comes close to his four-star cooking at Avenues. And though GE’s prices are lower than Avenues’ ever were, I didn’t crack a smile when a blaring eighties-to-indies soundtrack bounced around the hard surfaces of the rehabbed warehouse. Humor’s hard to come by when you can’t hear your companions—never mind the waiter.

But the gallery-district crowd must love shouting at one another over fancy cocktails, because the place is packed every night. They don’t seem to mind the bare wood tables either, nor the lack of bread service. Instead of bread, a server brings a napkin-lined copper-colored wire basket filled with designer-flavored popcorn, perhaps dusted with sweet curry or sun-dried tomato and oregano. Fun, but popcorn has to be freshly popped to be enjoyable, and GE’s was consistently on the telltale rubbery side.

Ever clever, Bowles tops a thick square of Kobe beef tartare with wonderful smoked ice cream and fresh potato chips, and garnishes it with baby watercress and Béarnaise gêlée: a delicious and playful spin on steak frites. Creamy artichoke bisque poured over a disk of preserved lemon, onion jam, and haricots verts crowned with fried leeks steered clear of whimsy but proved just as good.

Bowles’s quirky foie-lipops made the move with him from Avenues. He blends foie gras with cream, freezes the concoction into balls on sticks, and—for a bit of fireworks—rolls them in strawberry Pop Rocks. Truffled potato gnocchi with grilled asparagus and a sunny-side-up egg with shaved Pecorino Romano seems perfectly serviceable, but hardly in the league of the tartare, the bisque, or the foie gras.

BLT-style salmon, though, is as good as anything Bowles did at Avenues. He slow-poaches the bright red fish in olive oil and serves it like a salad at room temperature on toasted brioche: The B is pancetta vinaigrette; the L is baby frisée; the T, heirloom tomatoes dressed with basil essence. It’s a gem, but my dining companion wouldn’t stop talking about her pork prime rib. The kitchen grills a three-inch-thick pork chop, finishes it in the oven, coats it in root-beer-based barbecue sauce, and sets it on a bed of creamy grits, zesty collard greens, and a peach chutney that recalls old-fashioned pickled peaches. She’s right: This tender chop and all its fixings make a magnificent meal.

Sour lemon napoleon was the best dessert I tried, made with thin basil-dotted phyllo, layered with tangy-sweet lemon curd, and served with a scoop of flawless blueberry sorbet. The jeans-and-sneakers waiters explain things pretty well—ours smartly suggested a bottle of spicy 2005 Les Sorcières grenache Côtes du Roussillon ($48)—but the food runners too often don’t know who gets what. That’s not four-star dining. Then again, maybe it will take a while for Bowles’s bistronomics to trickle down to the rest of us.

The Skinny

AVENUES The Peninsula Chicago, 108 E. Superior St.; 312-573-6754 Tip Despite the largess, save a little room for the phenomenal bread pairings that appear throughout the meal. Hours Dinner Tuesday-Saturday Tab (without wine, tax, or tip) Three menus: 4 courses ($75), 12 courses ($115), 15 to 20 courses ($140)

GRAHAM ELLIOT 217 W. Huron St.; 312-624-9975 Tip Some of that soundtrack may be by the talented Bowles himself. Hours Dinner Monday-Saturday Tab (without wine, tax, or tip) $50 to $65

Photograph: Chris Lake