You would be unlikely to spot one. They try not to make frequent repeat visits to minimise the chance of recognition, and often dine in pairs, posing as couples or business people. There are a mere dozen of these practitioners of gastronomic surveillance in Britain and only some hundred worldwide, and in their hands they hold careers and reputations.
If the life of a Michelin inspector (good salary, travel to faraway places, the best diet money can buy) seems enviable, that is because it is. Mortals have offices and factories for workplaces; these people earn their salaries dining at Gordon Ramsay and the Dorchester.
The release of the Michelin restaurant guide last month carried with it an inevitable range of emotions, from elation to disappointment. Happiness for Heston Blumenthal and his team at Dinner for their second star, likewise the Greenhouse in Mayfair, and relief at The Samling in Ambleside following the recovery of a lost star. Relief, also, at Ametsa at the Halkin Hotel in Belgravia, recipient of muted reviews following its opening but now vindicated by its first star.
But pain at L'Atelier de Joel Robuchon in the West End, reduced from two to one-star status, and on the Isle of Wight, where The Hambrough surrendered its place in the firmament.
There will be grumbles, inevitably, but the line from Michelin is consistent: the guide is about food, and nothing else.
"We do have a criterion for a star, and people do get very confused," says a seasoned inspector. "They think it's about the surroundings, service, number of staff, but it's about the food - the cooking, flavour, texture, technique. It doesn't have to be complicated, just good and good value for money, in clean surroundings. That's it. Very simple."
Not so simple if one is at the receiving end. The pursuit of a Michelin star, that supposedly simple indicator of a good meal, has become a life's quest for some chefs, and its retention the subject of enormous expenditure by others, in money, time, effort and stress. Michelin may claim simplicity of aim but the brand benefits enormously from its mystique. How many other publications, after all, command such attention on their release date?
The guide's perceived power can result in a loss of perspective by those striving in the kitchen's heat for culinary perfection.
"It can destroy a lot of young people's lives - those who make the guide the only purpose of their quest for excellence," says Raymond Blanc, owner of the two-star Le Manoir aux Quat' Saisons, in Oxfordshire. "That is dangerous. To lose a star is as dangerous as it is rewarding to gain a star."
The world owes Andre and Edouard Michelin for this twinkling source of obsession. The French brothers created the guide in 1900 as a promotional device for their tyre business, offering early motorists advice on roadside eateries. The Michelin star was born in 1926, developing in 1931 into the three-star system we see today. One star denotes "A very good restaurant in its category", two "Excellent cooking, worth a detour" and three "Exceptional cuisine, worth a special journey".
Of some 2000 entries in the British edition, a handful merit the three-star accolade.
About 20 command two stars and 140 a single star.
Michelin's British team spend about three weeks a month on the road, swapping regions periodically. All food and drink is paid for and attempts by owners to ingratiate themselves with suspected inspectors, such as offering free courses, will cut no ice.
"If we award a star or take one away, we know the difference it will make to somebody's business," says the inspector. "So we've got to be absolutely sure and go as many times as we have to in order to ensure consistency. So, for a two star, it could be three or four times in six months."
There are no enthusiastic amateurs among the inspectors. Drawn from the industry, kitchen or front-of-house, they remain unfazed by opulence.
"We go into some of the best hotels and restaurants in the world," says the inspector, who worked as a private chef on a yacht before joining the guide. "We are used to imposing, intimidating surroundings. It's never going to affect the way we think about the food."
Ruthlessly empirical then? "I'd like to think ruthless in a nice way."
Does she see a danger in chefs losing perspective as they take off in search of a star?
The name always mentioned at this point is Bernard Loiseau, a pillar of French cooking, who shot himself in 2003, apparently gripped by the fear, unfounded as it turned out, that he was about to lose his third star. Other chefs have simply given up trying to maintain the standard required for tri-stellar status, citing the toll on health. The stakes are real. A single star can boost takings by 20 per cent, and its loss can have an equal and opposite effect. The temperature in the industry has increased with the mutation of cooking into a form of showbusiness.
"If you're a great actor and make a great film, then there's an expectation that every single film you make after that is going to be as good, if not better," says Tim Allen, chef at London's Launceston Place in Kensington, awarded its star last year. "That's surely the same pressure psychologically as having a Michelin star. It's a natural instinct to fear things, and if you've got a star, losing it is the worst thing in the world."
Allen works 17-hour days, six days a week, rising at 7am and returning home at 1am.
"I miss my kids, but I love what I do. If you don't, there's no point doing it. Your job is to make people's social time a great experience, and that involves having none of your own."
Teams are everything at star level. Lose precious staff and it will tell. Atul Kochhar, whose Mayfair restaurant Benares is one of only half a dozen Indian restaurants in Britain with a star, says: "We try to keep the talent for as long as we can. I tell the boys who work for me, 'Please give me two or three years at least so I can give you a proper grounding'."
He is not a fan of creative tension.
"I've been through that style," he says, "I've seen what it does to people - let's call it an experimental mode of life - and I've come to understand that a calm character, friendly behaviour, works best."
There is always going to be some unhappiness over Michelin's conclusions but there appears to be a consensus at the top that it strives for accuracy. Even Raymond Blanc thinks that, and many think he was treated unfairly in not being awarded a third star years ago.
"At one stage it did irritate me," he says. "I knew we were three-star - we were so ahead of the field. I felt there was a degree of unfairness - people pulling certain strings. I don't know which strings, which people. There were a lot of politics in the past. I'm not dwelling on it. That was a long time ago.
"The guides are important, they have a raison d'etre. Personally, I would never give too much validity to any guide. I don't work for a Michelin star. I'm not a mercenary. I work for excellence."
Shaun Hill has been around the block enough times (three one-star restaurants) not to be overly alarmed by the little red book.
"Michelin has carefully nurtured a mystique in terms of being scientific but all awards are subjective," he says. "I always feel myself to be on the edge of what Michelin likes because I have outside lavatories here and maintain a fairly democratic view of food. I have never worked towards what I imagine Michelin are after - that is the great trap door that people fall through.
"You can agree or disagree with their findings but you can't disagree that they conduct their business in an objective manner."
To some, though, a Michelin star can seem like a burden, even a curse. During a recent conference of super-chefs in Berlin, the mood appeared to be swinging away from Michelin-inspired perfection towards greater informality.
"In the 80s and 90s we built palaces and now guests are intimidated to come in," said Michael Hoffmann of Margaux.
"After the stress of the day, they have more stress - which Champagne to choose, what to order. We aren't targeting the client any more. We need to keep our feet on the ground. Guests are looking for a relaxed atmosphere."
All professions suffer from a certain introspection and the importance accorded to Michelin may be less in the outside world than examiner and examined imagine.
The internet, with its infinity of food blogs and comment sites, threatens to undermine the guides.
"Brilliant!" says Blanc, "because customers are being given the right to write about their experience. Who is to say they are not qualified?"
In the meantime, Michelin rolls on. Christmas is not far off. Do the inspectors engage in a festive celebration?
"We do go out for a Christmas party," says our inspector. "In fact, we have three or four parties a year."
Where? "It varies. A country pub, somewhere in town, we mix it."
Imagine that, a dozen Michelin inspectors in one restaurant. Pity the chap who incinerates
the creme brulee.