This article was also published in the Financial Times.
To ensure any restaurant succeeds, restaurateurs have to work so closely and over so many hours with their chefs that parting is invariably painful and often traumatic.
And the parting can start in the most innocuous fashion. At the end of one of numerous encounters during the day, the chef may ask for a quiet word to announce that he believes that now is the right time to move on. The most disruptive outcome of all for the restaurateur is when the chef then says he is about to open his own restaurant, as this can lead to a far more wholesale departure with the sous chef, the pastry chef and possibly even the restaurant manager following in his wake.
Alternatively, a chef may just announce that for personal reasons it is time to move on, an eventuality that can present the restaurateur with the opportunity to change not just the style of the food but also the manner and delivery of the service. In most of today's better restaurants, the waiting staff are far more closely involved in finishing the dishes at the table – by pouring the soup or carving a piece of meat – but this requires a much higher level of communication between the kitchen and the restaurant than even a few years ago when waiters were merely plate carriers.
Marlon Abela (above left), the restaurateur behind the two branches of A Voce in Manhattan and Cassis, Umu, Morton's and The Greenhouse in London, recently faced this predicament when Antonin Bonnet, his chef of over five years' standing at The Greenhouse, quietly let him know that for family and professional reasons he wanted to head back to his native France.
Abela, who takes his food and wine very seriously, used this opportunity to instigate a worldwide search for Bonnet's replacement and while it is no surprise that he chose Arnaud Bignon (above right), another Frenchman, it is certainly highly unusual to have found one with the same initials. Nor was Bignon cooking in a most likely location – he had in fact just won his second Michelin star cooking at a restaurant just outside Athens. But empathy there must have been because the initial page of their new menu reads like a cri de coeur in which both Abela and Bignon announce that they are now partners in the new Greenhouse, which they plan to take to new culinary heights.
But the partners have some work to do to judge from our evening at The Greenhouse that was uneven in quality, a sensation that became obvious as we crossed its front door.
One of the great attractions of this particular restaurant is that to reach it can involve a walk through Berkeley Square, probably London's most romantic square, and then through a quiet mews. Ours was an idyllic stroll in the evening sunshine, but suddenly our eyes had to readjust to the internal gloom as we walked into the restaurant, where the management had insisted on turning the lights down far too low.
The low lighting not only lowered our spirits but also impeded one of the particular pleasures of visiting The Greenhouse, which is reading its wine list. This is vast; printed in small type; and incredibly comprehensive. This list may well hold the world record for the ratio of number of bottles on offer – all of which I was assured are stored on site in excellent conditions – to the number of seats in the restaurant.
For the adventurous it provides the key to some great bargains because, while there are pages of rare wines at relatively (though not rapaciously) exalted prices, there are some seriously underpriced and well-preserved gems. For a total of £78 we shared one glass of each of two elegant French wines, Le Soula Blanc 2007 from the Roussillon and a dry white Graves, Clos Floridène 2008, as our aperitif and over dessert shared a glass of Madeira. But the highlight was a bottle of 2000 Domaine Laureau, Bel Ouvrage, a Savennières from the invariably neglected Loire Valley. At £38 this was a wine that conveyed freshness and dense minerality overlaid by the charms of considerable bottle age. It was a real gem.
And so too was one dish, a first course described accurately in terms of its contents but somewhat frustratingly in terms of its presentation as Potato/smoked/romaine lettuce/oysters/shallots. What emerged was a thick but wonderfully light soup bound by egg yolks that showed genuine dexterity. There was also the requisite high level of technique in the delivery of our two fish main courses, cod and sea bass, but their accompaniments were disappointing. The consommé with the former was far too salty and overwhelmed the quinoa by its side while the cube of nori seaweed alongside the bass was bland and was virtually exactly the same shape and presentation as the foie gras first course and the macadamia parfait that followed. 
At the moment, The Greenhouse kitchen manifests two shortcomings. The first is that like so many chefs who move into central London from outside, Bignon is simply trying too hard – Claude Bosi was just the same when he first opened Hibiscus five years ago. Bignon needs to relax. And he needs to spend whatever time he has away from his own kitchen eating around to begin to emphasise more strongly the natural flavours of all that he is cooking with. Then the pleasures of his cooking may come to match those of the wine list.
The Greenhouse 27A Hays Mews, London W1J 5NY +44 (0)207 499 3331