Boston-born, 94-year-old non-fiction film wizard Frederick Wiseman turns his gaze to one of the most celebrated restaurants in the world in “Menus-Plaisirs – Les Troisgros,” and I hesitate to say that the results are delicious. Even at a feast-worthy length of 240 minutes, I remained fully engrossed in this unflinchingly exhaustive examination of the way a French restaurant that has had three Michelin stars for over 50 years operates. Anyone wondering if Wiseman made the film in order to get to eat at Le Bois sans Feiulles in France’s Loire Valley for as long as it took to make the film is not alone.

Over the course of the drama, we spend time with restaurateur-patriarch Michel Troisgros, a master of the history of the culinary arts in France and the Far East, and learn about his very high standards as he passes the baton to his son Cesar, while his younger son Leo runs another family restaurant La Colline. We also hear about a third Troisgros restaurant. Guests at these establishments, especially Les Troisgros, often stay at a hotel also operated by the Troisgros family.

At first, we see how greens and vegetables are chosen. But soon enough the conversation shifts to fish: trout, pike and perch. Have you had a quenelle? Could you master a mousseline? In addition to the produce market, we visit a fromagerie, where cheeses are made and aged, a vineyard and a cattle ranch, where we learn about the latest techniques for raising plants and animals in organic, renewable and humane ways. Throughout the film, Wiseman will divide his time between the restaurant and its grounds and the nearby farms and markets where the food is examined and procured.

In the kitchen, a young chef steps away to read a recipe out of Escoffier’s “Le Guide Culinaire.” We watch as artichokes and asparagus are trimmed, cockles sorted, crayfish corralled. We hear about Cesar’s design for a completely open kitchen, divided between hot and cold, where everything from meat and fish to breads, cakes and pastries can be made. Brains and other sweetbreads are on the menu as are humble hams and pigs’ feet. Efficiency, order and cleanliness reign supreme. No one is screaming or having a meltdown. Gordon Ramsay would not feel at home here.

Bottles of La Tache and Puligny-Montrachet might be had for a breathtaking 10,000 euros or more. Assistants and servers are sent to nearby woods to collect flowers to decorate the plates. A farmer explains how his cattle are directed in the field using movable fences to feed evenly on the grass. Hams are smoked, bread baked. The entire, precision operation suggests something military. Menus are discussed and written. A cheesemonger rattles off the names of 30 varieties on his tray.

For all of his career, Wiseman has been pulling aside the curtain on different institutions: a public hospital (“Titicut Follies”), library (“Ex Libris”), park (“Central Park”), racetrack “Racetrack”), zoo (“Zoo”) and ballet troupe (“La Danse”). Here, he gives us a restaurant surpassing in exclusivity the one in the recent (and not very good) foodie satire “The Menu” with Ralph Fiennes and Anya Taylor-Joy. Le Bois sans Feiulles (The Forest Without Leaves) is a restaurant for the 1%. It is a family restaurant, if your family’s name is Bezos, a subject Wiseman strangely does not address.

Toward the end, we visit a humble shepherd-farmer who supplies the restaurant with goat cheese and identifies his goats by name. A vineyard owner speaks passionately about plants that do not “compete” with the vines. Beekeepers proffer honey. Back at the restaurant, tablecloths are ironed; vases placed on tables, a helicopter lands on a patch of grass outside. We visit a wine cellar full of treasures. Cesar mingles with his guests. How many more helicopters can be expected?

(“Menus-Plaisirs – Les Troisgros” contains obscenely expensive food and drink)

“Menus-Plaisirs – Les Troisgros”

Not Rated. In French with subtitles. At the Coolidge Corner Theater

Grade: A-

A dish is plated in a scene from “Les Menus Plaisirs Les Troisgrois.” (Photo Zipporah Films)