The Windmill's Oisín Rogers 'excited and nervous' ahead of Mayfair restaurant launch

The 26-cover dining room, which is already almost fully booked for its first week, will offer a menu featuring poached rock oysters, bone marrow straws, mushroom and truffle pie, and summer fruit suet pudding, each with a suggested wine pairing.

Richardson, who will continue to oversee the kitchen at the Guinea Grill, located a few minutes' walk away on Bruton Place, said he had been working on the new dishes during lockdown. He said: "Creating new menus and dishes weekly will be a fantastic challenge and will lead to a vibrant and eclectic evolving menu. This really is an exciting time."

The downstairs pub will continue to offer its award-winning pies, of which it sells hundreds every day, and Young's cask beers, with secondary fermentation being overseen in the cellar in the "old-fashioned way".

Richardson, who will be working alongside Windmill head chef Luciana Balan and restaurant manager Dominic Rowntree, added: "This is a chance for us to move outside our comfort zone and work with ingredients and techniques we do not always have time to explore."

"Creating new menus and dishes weekly will be a fantastic challenge and will lead to a vibrant and eclectic evolving menu. This really is an exciting time."

The three-storey building's basement kitchen means that dishes will be delivered to the first-floor dining room via a dumb waiter. As part of service, Richardson will be positioned at a kitchen station in the dining room, equipped with induction hobs, a sous-vide and blowtorch, in order to add the finishing touches and garnishes to dishes in front of guests.

Rogers, who took over the Windmill at the beginning of March, said Richardson was "a fan of incredibly good ingredients, rich sauces and French-style cooking" and that he had worked with him on various restaurant projects over the years, including at the Guinea, where he had held the position of head chef for the past three years.

He admitted he had been "really worried" about footfall in central London as the capital emerged from lockdown but having now reopened both Mayfair pubs, he concluded: "We've opened and things have improved and are improving.

"We are cracking on and you can come to either of our pubs and have a brilliant time."