La Grenouille, the epitome of fine French dining, has been transformed into a delicious chain restaurant but it still looks the same

La Grenouille, widely acknowledged as the city’s prettiest restaurant for more than a half-century, closed last fall.But its gorgeous ghost is back at 3 E.

52nd Street, where frogs’ legs have given way to Beijing-style duck.The former home of classic French cuisine has surprisingly been reborn as a location of iDen & Quanjude Beijing Duck House — an empire of fowl-focused restaurants that originated in 1864 in the Chinese capital.Remarkably, the new owners have lovingly preserved the timeless look of La Grenouille.General manager Wayne Pan explained, “We had many thoughts about redesigning it like our restaurant in Vancouver” — the Quanjude brand’s only other North American location that’s elegant in a cool, modern style.

(There are about fifty in China.)“But people suggested not to do that, and to keep most of the old La Grenouille, because it has so many good memories for New Yorkers,” Pan said.The new restaurant’s owner, Andy Zhang, also owns the Canadian location, and he bought the chateau-like 1871 former carriage house in Midtown NYC  last year for $14.2 million.He and his wife divide their time between NYC and Vancouver and had enjoyed dining at La Grenouille.

“They made a decision to preserve it,” Pan explained. The jewel-box, 80-seat dining room looks almost exactly as it did when its predecessor drew luminaries from Frank Sinatra and Elizabeth Taylor to Blake Lively and Adrien Brody.The room’s seductively retro crimson banquettes, gold fabric walls, beveled mirrors, and flattering lighting — from recessed ceiling fixtures and sconces — have all been perfectly preserved like a ship in a bottle.

An abundance of fresh flowers in the L-shaped dining room further keep the La Grenouille spirit alive.Only the wall paintings are new, although in the same Belle Epoque style as before.

The vibe is still romantic, sexy and hushed, save for classical strains of Haydn, Schumann and Mendelssohn.The food, however, is a differ...