Recipe 695 in Auguste Escoffier's "Le Guide Culinaire" is Puree Palestine, a sunchoke and roasted hazelnut soup. The five-sentence recipe, much like the 5,011 others in the book, is rather vague. Few recipes even call for salt. Dubbed "Escoffier" for short, "Le Guide Culinaire" is Textbook One of French gastronomy and points in a general direction rather than offering turn-by-turn maps.

In researching the 100-plus potential dishes for their forthcoming restaurant, called Next, Alinea chefs Grant Achatz and Dave Beran cooked the sunchoke soup as Escoffier indicated. The result was a "cream bomb," Achatz recalled, lacking acid to counterbalance its intense richness. But Beran, the 29-year-old Tru and MK alumnus who will head Next's kitchen, suggested serving the soup as Escoffier intended and gauging reaction.

The response was polarizing. Some who sampled the soup thought it tasted "French" and "perfect"; others couldn't finish the bowl. And therein lay a philosophical debate behind this most ambitious sequel from the Alinea team: When a restaurant promises to transport diners everywhere and to every era, should authenticity carry as much weight as progress? It's a battle the Next team hasn't entirely resolved.

The success of Alinea — which recently got top honors from Michelin in the form of three stars — has afforded Achatz and restaurant partner Nick Kokonas a rare chance in the restaurant industry: bankroll a wildly radical dining concept. Next, scheduled to open in Fulton Market at the end of the month, will feature a menu that will change every three months, tied to a location and time period. Paris 1906 is its inaugural theme; Thai street food (time period undetermined) will follow in June. For future menus, Achatz has floated the idea of Prohibition-era Chicago, New York circa "Mad Men" and Hong Kong 2036. He's even considering "The French Laundry — Oct. 16, 1996," re-creating dishes from Achatz's first day working for Thomas Keller (and possibly bringing in Keller for a weeklong guest stint). It is the most anticipated restaurant opening Chicago has seen, period.