“I respect what ‘Stairway to Heaven’ has done for me,” the chef said. “I respect how the legend of that has helped this place grow. But I’m doing this for creative reasons.”

In essence, Mr. Dufresne explained, he and his highly skilled, intensely collaborative team were at risk of winding up in a state of suspended animation. Being tethered to older dishes can make it harder for people to notice that you are still exploring new territory.

And exploring new territory has always been his core mission. Henceforth, he intends to do even more of it by stripping away the à la carte menu at WD-50 and offering diners a choice between two tasting menus.

The primary one, priced at $155, will consist of a dozen or so courses, each of which will not only be new to the restaurant, but, as is usually the case with cuisine de Wylie, also new to human civilization itself. This spring, in the first version of that menu, diners will find red-hued noodles fashioned from lobster roe, and shiny-skinned lamb sweetbreads in puddles of a sauce made of buttermilk and nasturtium blossoms.

(A second menu, which Mr. Dufresne calls “From the Vault,” in tribute to the Grateful Dead, will trot out a selection of five “greatest hits” from previous offerings, for $75. And customers will still be able to sidle up to the restaurant’s bar and request a few à la carte dishes.)

Mr. Dufresne is an intrinsically American pioneer, so it makes sense that, in the language of the menu, many of the new creations sound like stolid heartland fare (crab cakes, brisket, root-beer ribs, fried green tomatoes, Key lime pie, even what you might describe as an elevated twist on a TV dinner). On the plate, though, they psychedelically thwart what your eyes, teeth and taste buds expect.

The “TV dinner” (which can also be compared to a deconstructed potpie, but which was actually inspired by a Chinese recipe that Mr. Dufresne found in one of the 1,400 cookbooks he owns) involves the yolk of a duck egg that’s been bathed in amaro, the strident Italian spirit, after having been cured for six hours in salt and sugar so that its texture thickens. It is paired with succulent chicken confit and “peas ’n’ carrots.” The carrots are carrots, sliced thin and curled up like ribbons. The peas are not peas, per se, but tiny balls of carrot that have been rolled in green-pea powder.