Bonnet, who trained under French chef Michel Bras, took over from Bjorn van der Horst in February 2006. He will be replaced by Arnaud Bignon in March next year who will join the restaurant from the two Michelin-starred restaurant Spondi in Athens.
Bignon, whose pursuit of 'fresh and original flavour combinations' has become his signature, previously worked as sous chef under Eric Frechon at The Bristol.
He is known for combining his French training with contemporary techniques and his philosophy is based 'around finding perfect harmony and balance in all his dishes, often playing with acidulated flavours to enhance the main ingredient.'
MARC (Marlon Abela Restaurant Corporation) chairmain Marlon Abela said: "Arnaud Bignon is a phenomenal and very talented chef, who joins us having accomplished a great deal at such a young age. His arrival will be a welcome addition to the London fine dining scene. It is a fantastic opportunity for us to develop The Greenhouse’s alreadyoutstanding reputation and take it to the next level.”
The Greenhouse opened its doors in Mayfair in 1977 with Brian Turner as head chef.
It is one of eight restaurants and private members' clubs currently operated by MARC Restaurants, four of which - The Greenhouse, Umu and Cassis restaurants and Morton's private members' club - are situated in London.
Earlier this year Abela bought the former Bertorelli's site in Fitzrovia with plans to develop it into another restaurant.