Richard E Grant turns sniffing a bowl of soup into a sort of sublime performance art. It helps that he has the perfect nose for the job - prominent and rubbery, with nostrils that appear to take on their own life as he gets stuck in.
"Divine," he trills, that patrician proboscis practically wobbling. "Absolutely superb… How can you resist?"
We're having lunch at Brown Thomas's supremely swanky top floor restaurant. Or at least Grant is - unaware that the plan was for thespian and journalist to break bread together, I've already stuffed my face and so am sitting out the feast laid before us.
Dinner for one, with a reporter taking notes, is the definition of awkward. Yet Grant is such a natural-born raconteur he's soon off to the races anyway. Between mouthfuls, the actor holds forth on his recent appearance in Game of Thrones ("fantastic but I wish I'd been in more of it because it's so great"), his upcoming turn in the latest Wolverine movie and his memories of Withnail and I, the twinklingly miserable 1980s classic to which he owes his career.
It's a proper gush - yet Grant isn't one of those luvvy bores desperate for an audience. He's convivial and is soon peppering me with questions too (Who was the rudest person I've ever interviewed? What did I have for lunch?).
It's been a banter-filled morning for the 59-year-old, who has spent the morning pottering around Dublin chatting with locals for a promotional film he's making for Tourism Ireland.
But Grant (above) has also just launched his latest bespoke fragrance, which is what brings him to the store for our tête-à-tête. Jack - Piccadilly '69 is his third unisex scent and is inspired by the aromas of late 1960s London, where he washed up as a wide-eyed 12-year-old and was immediately bowled off his feet.
"We were on holidays and I especially remember Piccadilly Circus and all the hippies smelling of patchouli oil. I was taken to see the musical Hair at Shaftesbury Avenue. It had full frontal nudity… amazing. So that's why I named it after 1969."
Setting the now thoroughly empty bowl of soup to one side, Grant outlines his unified theory of scent and human psychology.
"Your sense of smell is the shortest synaptic leap in the brain," he says. "You could smell something that you haven't experienced since you were six years old. The moment you do, it will bring you back to that place and time."
I'm beginning to suspect Grant is hamming up his love of a good sniff for my benefit. He's already extravagantly breathed in the aromas of the leather banquette into which we are squeezed and plunges his nose into his fish course upon its arrival. The exhalations are so loud they can probably be heard across the store.
Yet his enthusiasm for fragrance is, without question, heartfelt. Jack is entirely self-financed, a cottage business on which he toils with his wife, Joan, and 27-year-old daughter, Olivia. Moreover, a dive into the archives confirms he's been sniffing his way through encounters with journalists long before he launched a perfume business and was using his nose to sell a product.
"It has been my secret passion since childhood," he nods. "When I was 12 I tried to make perfume as a birthday present. It didn't work out. But I was always fascinated with it. I have compulsively sniffed everything - it always struck me as the most natural thing in the world." Acting gives him a licence to indulge this ardour to the full. "For Wolverine III we were in Louisiana, Mississippi and New Mexico. New Orleans is so humid - Bourbon Street essentially smells of pizza, beer and vomit. Especially when it's 100 degrees. Then you go into the desert and the plants in New Mexico have such a distinct dry scent… It almost borders on: 'Is this a good smell or a bad smell?'"
Movie sets, he reports, smell of money and high stakes. "You're around a crew of 300 people and it is a very machismo atmosphere. The smell of the studio and the lighting and the paint is incredibly distinct. I've never been in a theatre that smells like that."
Does he plunge into airport duty free, sniffing every last perfume?
"A lot of the big brands are done by committee," he says, wincing a bit. "Celebrity scents are to a large extent made as a marketing exercise."
I'm dying to ask him about Game of Thrones in which he played to type as a luvvy actor performing in a bawdy revue. Grant is a huge fan and firmly of the opinion that we are living through a golden age of television.
"We did the interiors in Belfast, at Titanic Studios, the old paint halls. The exteriors were shot north of Barcelona. It was like being in a movie - as it would be considering they spent $11m per episode. Its reach is phenomenal. On Wolverine, I was working in New Mexico in a town of 600. And there wasn't a day that someone would not come up to me and say: 'I saw you in Game of Thrones.' It amazes me. I just wish I'd been in more episodes."
Grant's chipperness has an almost electric hum and it's tempting to interpret this as a conscious riposte of the many slings and arrows life has directed at him. His father, the last director of education of what was then the British protectorate of Swaziland, was an alcoholic who once tried to shoot Grant when his son accidentally knocked a whiskey bottle. Bored and neglected, his mother took solace in infidelity. As a young boy he watched her canoodle with a friend in the family car as his father lay passed out in the back seat. "It was a poisonous secret for a child to have to keep," he would later say. "I was gobsmacked."
He returned to London in 1982, after the death of his father. Brought up in a colonial time capsule, he arrived in Britain like a visitor from another epoch ("you speak English like someone from the 1950s," he was told by Charles Sturridge, director of Brideshead Revisited).
Success was not immediate - it would be five years until Withnail, for which he was second pick behind Daniel Day-Lewis, lifted him from obscurity. He has since carved a niche as British drama's Mr Reliable - seldom required to carry a movie, but an endearing presence adding sparkle to the drabbest script (we can, for instance, thank him for Spice World being even vaguely watchable).
Grant is just back from holidays - two weeks in the south of France in the company of Bruce Robinson, writer and director of Withnail and I. Close to 30 years on, the movie remains Grant's masterpiece, his turn as vain and needy failed actor Withnail one of the great British screen performances.
He is gracious about the film and its impact on his career and not at all precious about the degree to which it has overshadowed all that followed.
"What makes that character so funny is the character's warped sense of entitlement - in complete disproportion to his lack of talent. When I received the script, I knew it was like nothing I'd ever read before. I thought there was no chance they would cast a complete unknown, with no screen or TV experience. It literally changed my life. If Daniel Day-Lewis had done it, I would not be sitting in Brown Thomas eating with you today."