In a statement posted on Twitter on 31 December, the chef wrote: “After 20 incredible years, it is time for me to move on from Bray for a new chapter and to take on fresh challenges. I will initially be spending some time with my family as I prepare for the new and exciting journey ahead.
“I am eternally grateful to all of you for the knowledge and memories I have gathered working with Heston and the group and would like to thank all the brilliant people past and present that have made the last 20 years nothing short of extraordinary.
“I wish everyone continued success for the future and I am very proud to be able to say I have been part of the magic of Heston’s world.”
Palmer-Watts began working as a sous chef at The Fat Duck in Bray in 2001 during the restaurant’s ascendancy to three-Michelin-star status.
He became head chef in 2003 aged just 25 and oversaw the opening of London's Dinner by Heston Blumenthal in 2011.
The chef also launched The Fat Duck’s annual Inspirational Lunch day in 2018, where hospitality and catering students are invited for a free meal at the three-star restaurant.
His departure comes at amid a tough time for Blumenthal’s business. The Fat Duck saw pre-tax profits drop from £533,145 to £297,788 for the 12 months to 27 May 2018, while turnover rose slightly to £6.7m.
Recent accounts for the restaurant’s parent company Snail Porridge state the group is undergoing a ‘period of transition’ which include cost-saving measures and ‘several new projects’.