Mr. Dionot opened L’Academie de Cuisine in Bethesda, Md., in 1976, catering mainly to home cooks, with an inaugural lesson on the preparation of shrimp quenelles, salade Niçoise and a berry tart.
French cooking, popularized in the preceding years by Julia Child, proved a ripe business opportunity, and steadily Mr. Dionot attracted increasing numbers of students with his approachable manner and expert technique.
His amateur students over the years included lawyers, nuclear engineers and surgeons. One student told The Washington Post that she and her husband attended classes “like some people go to the symphony or the opera.”
Over time, Mr. Dionot expanded his operation with an accredited professional cooking program in Gaithersburg, Md., that became known as one of the best courses of its kind in the United States. Among its instructors was White House pastry chef Roland Mesnier.
Alumni included Carla Hall of the television programs “The Chew” and “Top Chef,” as well as the acclaimed Washington chefs Aaron Silverman of Rose’s Luxury and Pineapple & Pearls, Nicholas Stefanelli of Masseria and Katsuya Fukushima of Daikaya. Other graduates went on to careers at 1789, the Willard Hotel and Kinkead’s brasserie.
In all, tens of thousands of students passed through L’Academie de Cuisine before it closed in 2017 — a casualty, The Post reported at the time, of low enrollment and deteriorating finances.
L’Academie de Cuisine was widely considered to have contributed to a flowering of Washington’s culinary landscape, helping transform the capital from a backwater of food to a destination for more sophisticated dining experiences.
Whether a student was training to become a professional chef or a more cultivated home cook, Mr. Dionot emphasized the “four P’s”: purchasing, preparation, presentation and palate. He trained his students to buy the proper ingredients, to slice and sauté them with expert skill, and to deliver dishes to the table in a manner that was as pleasing to the eye as it was to the tongue. He demanded precision even in the matter of apron-tying.
In all his years of teaching French cooking, Mr. Dionot professed never to have repeated a menu. At his final regular lesson, he coached students in the preparation of sautéed scallops with Belgian endive, roast chicken with potato gratin and the traditional Christmas dessert called buche de Noël.
“They were divine,” food writer Carole Sugarman wrote in the Montgomery County publication MoCo360.
François Marie Jacques Dionot was born in Reims, in northeastern France, on Jan. 23, 1945. His father was an engineer. His mother, a secretary, and his grandmother were both fine cooks.
“I used to love to watch [them] in the kitchen,” Mr. Dionot told The Post. “But it was their domain. Men were not allowed.”
Mr. Dionot lived briefly with his family in Algeria during the former French colony’s war of independence. He studied in Germany before moving to Switzerland at 18 to undertake culinary training at what was then the Ecole Hôtelière de Lausanne.
In 1968, Mr. Dionot moved to the United States, working at restaurants and hotels in New York and New Jersey before opening L’Academie de Cuisine with a business partner. He lived for many years in North Potomac, Md., and moved to Gainesville last year.
Survivors include his wife of 46 years, the former Patrice Waldron of Gainesville; three children, Christophe Dionot of Silver Spring, Md., Clarice Gutman of Clifton, Va., and Laurent Dionot of Mount Laurel, N.J.; three brothers; and six grandchildren.
For all the rigor of his lessons, Mr. Dionot taught his students that they would know they had truly arrived as cooks when they no longer felt obliged to refer constantly to a recipe.
“Read the recipe two or three times to understand it,” he counseled them. “Then put it in a drawer and cook. That’s cooking.”