Ferran Adria’s El Bulli is widely regarded as perhaps the most innovative and influential restaurant in history, specializing in a style of cooking known as molecular gastronomy. Adria’s essential idea was to deconstruct food as a concept and reorient the notion of cuisine as we know it. Sometimes, this led him to some radical departures His menu frequently included such curious items as “carrot air,” “potato foam gnocchi,” and “parmesan marshmallows.”

Unfortunately, those interested in trying Adria’s unique dishes are out of luck. El Bulli, located in Catalonia, closed its doors in 2011, its website claiming the restaurant had “completed its journey.” So unless you can sang a table at Next, the Chicago restaurant currently paying tribute to Adria and his work by serving re-conceptualized versions of his food, the next best thing is Gereon Wetzel’s documentary, “El Bulli: Cooking in Progress,” back again by popular demand for yet another run at the Gene Siskel Film Center, 164 N. State St.

Six months out of every year, Adria closed El Bulli to formulate a new menu for the upcoming season. “Cooking in Progress” chronicles the creation of the restaurant’s final menu. From there, he and his close group of assistants begin the painstaking process of perfecting ideas such as a dish of “ravioli whose pasta vanishes.”

As meticulous as Adria and his crew may be, their method isn’t an exact science. Months of trial and error is the name of the game. Some dishes fail to move beyond the idea phase, while others undergo so many transformations that they become virtually unrecognizable from their initial design. Wetzel captures it all, observing the work with a sort of hushed curiosity.

Cinema verite has long been the preferred approach for many modernist documentarians, and considering El Bulli is the bellwether of modernist cuisine, the two styles marry nicely. There are no talking head interviews in “Cooking in Progress,” nor is there any voiceover narration. Wetzel simply lets the camera capture the moment, relying on the discussions that transpire in what can be aptly labeled as Adria’s laboratory to propel the narrative forward.

Less patient viewers may become aggravated by the seeming lack of drama, but with both Wetzel and Adria, the pleasure is in the discovery. Judging from the film, Adria is a person who sees the world as being composed of various elements that ought to be deconstructed in order to realize their true value. Accordingly, Wetzel makes sure to show us even the most innocuous moments of Adria’s process so that when everything finally comes together, the level of detail will prove that much more profound.

That said, when the film finally does reach its intended climax—the menu is finalized and the restaurant reopens—things get less interesting. Wetzel spends most of his time in the back of the house, illustrating the workmanlike procedures of El Bulli’s dozens of chefs as they arrange each plate with laser-like precision. With Adria’s maniacal conceptualizing complete, he’s free to rest on his laurels. Unfortunately, Wetzel follows suit, and “Cooking in Progress” quickly abandons its inquisitive mise-en-scene in favor of reflecting the ritualism of El Bulli’s employees.

Although one of the film’s central themes is the idea of labor and its many forms, Wetzel’s abrupt shift in tone doesn’t go unnoticed. Still, probably not unlike Adria’s food, “Cooking in Progress” goes down easy as an intriguing look into one of the world’s most fascinating minds.