Diego Masciaga is stepping down from his role as general manager of the Waterside Inn after 30 years of service.
Masciaga will step down from both his general manager and director positions at the Roux family's three-Michelin-starred restaurant in Bray, Berkshire on Sunday 3 June, to focus on motivational speaking and customer service consultancy.
Assistant manager Frédéric Poulette, who has been at the Waterside Inn for 14 years, will be his successor.
"Having been synonymous with the Waterside Inn for 30 years, Diego has decided to introduce a little more flexibility into his life, pursuing interests that will include passing on his extraordinary skills and experience to young people," said Michel Roux Sr, who described Masciaga as "part of the family".
"We are fortunate that Diego will maintain his close ties with us and may return for special events and support behind the scenes when needed. We wish our Diego all the luck in the world," he added.
Roux Sr described Poulette as "eminently suited by his personal qualities and experience for the role".
"What I leave behind are hundreds of staff that I have trained [here], now they're all over the world. The pupil should beat the master, and some of them have done that, and I'm so proud of them.
"The best thing about working here has been to see thousands of guests leaving happy and to see the place grow. I always tried to give as much freedom as I could give to my boss Michel, and never bother him for anything."
He added: "I've been here for 30 years because my wife allowed me to be here 30 years. My two daughters, in their lives, have never seen their father on Christmas Day. That it what people should understand about this profession - it's not a profession, it's not a job, it's a life."
Born in Italy, Masciaga worked in France before coming to London to work at the Roux family's three-Michelin-starred Le Gavroche restaurant in London 1983-5.
After a year as restaurant manager of Le Mazarin in London and returning to France to work at Restaurant Alain Chapel in Mionnay, he joined the Waterside Inn restaurant in 1988.
He was awarded the Cavaliere Ordine al Merito della Repubblica Italiana (the equivalent of the knighthood) in 2012 by the Italian Government in recognition of his contribution to the hospitality industry and for supporting young people in the profession. In 2010 he became only the third recipient of the Grand Prix de l'Art de la Salle from L'Académie Internationale de Gastronomie.