It's probably mere coincidence that star chefs are careening madly all over town now that subway-bus transfers are free. Montrachet's top whisk goes off to a range all his own, and Tropica's chef leaps into the breach. Patroon's kitchen commander signs on at Tropica, and the presiding cook at ë44' trundles crosstown to Patroon. Over burgers at J.G. Melon's, restaurateur Ken Aretsky lures Tom Valenti back from the netherworld of consulting to the stove at Butterfield 81. In no time, a lurk of taxis will be clogging the narrow side street as Valenti fans bid for orchestra seats at his lamb-shank revival.

        Butterfield has its loyal devotees, but it had virtually faded into its out-of-the-way streetscape and off the radar of the stomach-obsessed. Now, to spruce up the vintage neighborhood saloon for a star of Valenti's wattage, bare tables have been padded and cloaked. Leather has replaced the no-slide crushed-velvet banquettes. Both men insist there's a wee lumen of new light, but not at our table, where we're passing the votive candle to read the menu. No need to struggle: You can close your eyes and point. Faithful pilgrims who trailed him from Alison on Dominick to Cascabel will find Valenti's robust and lyrical cooking better than ever.

        Not that he's reinvented the bean or created a new vocabulary. Spring means morels, favas, and baby asparagus, same old same old, but startlingly new and delicious. Gently smoked sturgeon lies like a shawl across a perfect round of poached egg in a cluster of frisÈe dotted with crunchy nuggets of bacon. Fragile packages of sweet-pea agnolotti swim in a Parmesan-enriched broth. Plump little mussels and artichokes in a mesclun-haricots verts toss fill your mouth with a dozen flavors. Just when I long to be spared yet another listless salmon, his silken gravlax reminds me why this fish was once prized. Scented with mustard oil and jeweled with caviar, it clings to a chickpea pancake. As for his nuttily crumbed pork-confit-and-potato sandwiches, nested in a salad of bitter greens punctuated with slivers of cornichon and pickled onion, I wouldn't be surprised if he sold his soul to Satan for the recipe. Even a casual extra like the garlicky hummus to spread on warmed baguette is irresistible. I was dashed when Valenti replaced it one night with purple olives, but fat is fat and our foursome put away two saucers full.

        What is this man's obsession with the pig? Without Porky, Valenti would have been forced to be a forest ranger or an accountant. He scatters lardons everywhere. An unseemly meeting of bacon, veal jus, and red-lentil mash adds flavor clout to rich Chilean sea bass. "I'm a madman," he confesses. "I'm so bad. But pork tenderloin would be dry if I didn't wrap it in bacon. I tell the waiters to let people know the bacon on the bass is optional -- I don't want to frighten customers away." His mythic lamb shank is inevitable, and all the fresh m¸che sprigs in the world can't disguise the obscene voluptuousness of its soft polenta. Parmesan custard and a summer-truffle sauce heighten the pleasure of squab roasted to caramelized perfection. Why settle for chicken if you can have this miraculously moist rabbit with root-vegetable purÈe, or a first-rate steak, or even a sensible rendition of crusty skate with braised cabbage? Because if you can't remember what chicken used to taste like, this chewy Amish bird with a crackling skin makes it real again (and these may be the best mashed potatoes around).

        If you split a bottle of wine -- the list is eclectic and uptown, with only five wines under $30 -- two of you are likely to drop $70 apiece. Prices of appetizers (from $8 to $12) and those of entrÈes ($21 to $27) seem high for a neighborhood joint, I suppose, but fair enough for world-class dining. In a terrain this exuberant, desserts may seem modest, if not constricted: The small lemon cake with its itsy dribble of huckleberry. The modest hockey puck of chocolate. A cakey blueberry tart that tastes like Mom's on one of her tentative days. But the tropical tang of the passion-fruit creme frauche panna cotta makes up for any slight.

        Valenti is still surprised to find himself on 81st Street: "I think of myself as a downtown person. In my insecurity, I always felt better in an out-of-the-way location so I knew people came for the food. But it's nice having a support system from all these tall buildings." Fifty or 60 seats -- counting the summertime deuces on the sidewalk -- feel small-time for Valenti. He and Aretsky agree they might do another spot together one day. But this warm-up suits them both for now. Meanwhile, passersby can catch the chef in the morning through the kitchen's storefront window, starting the shanks and the custards. Look for the ponytail.

Butterfield 81, 170 East 81st Street 212 288 2700