Walking up London's Northumberland Avenue, you wouldn't know that it was there. Look up and you see only the vast Portland stoned edifices of a Britain at the top of its imperial game. The buildings are, shall we say, unsympathetic; it is about as far from a pastoral vision as it's possible to get. And yet if you could look down on one of the bigger buildings, the Corinthia Hotel, you would see something quite different: a small forest of tomato plants.
For the past year, Garry Hollihead, the executive head chef of the hotel, the man who devises all the menus for everything from room service to the up-scale Northall restaurant, has been quietly making a little garden for himself.
And he has been doing this in a greenhouse that looks as though it came from his local Wickes.
"I can't grow enough products for the whole hotel," says Hollihead, as if by apology. "There is only limited roof space with all those air-con units dotted around." It's not exactly surprising that he can't grow enough, since the hotel has 251 rooms.
But, still, he's very proud of what he does grow.
There are his herbs first off, lemon vibena and lemon balm (a particular favourite, he uses it in ravioli and shellfish bisque in the Northall and a few desserts) and thyme. And this year he has also grown strawberries, lots of them, in fact.
"I had 40 plants in pots. I used them in the afternoon teas. I had a display in the hotel courtyard and people would come in and then decide which they wanted with their scone. People liked that – it's personal."
It certainly establishes a connection between the diners and their food, but Hollihead is keen on it for a couple of other reasons, too. The first is that thing at the heart of all good cooking: making sure your ingredients have a top-notch provenance. If you grow your own tomatoes on the roof of your establishment, as he does, you know they are going to be decent.
His other reason is more personal and rather English. He likes pottering about.
"I like being up there, even if it is only for 20 minutes in the morning watering and the same at night. It gives me time to think. I get this increased control over the varieties, the different flavours and, more than that, I get inspired."
It's not hard to see why, given that the view from his greenhouse takes in London Eye, Nelson's column and Big Ben.
Does he have plans for any more greenhouses? Perhaps one, he says, but the posh suites that look out onto the roof make it difficult.
"I try hard not to see anyone, while I am up there. But they can certainly see me," he says.
Last year I was going into the Corinthia as Rihanna was coming out. There was a terrific scrum, flashbulbs, wailing teenagers, the lot.
I wonder if, before she left, she ever looked out of her top-floor suite and spotted Garry tending his tomatoes?
That's a thought I enjoy.