Sharply dressed in a tweed bomber and jeans, Jamie Oliver is strikingly Jamie Oliver. Periodically he runs his hands through his signature locks, just a slight pause before resuming his charmingly lisped, Essex-edged dialogue that runs – like his many and varied ventures – at polished high speed. The enthusiasm that has made him so accessible on-screen is omnipresent and undeniably infectious.

We’re sitting in the back corner of his new restaurant, the second branch of Barbecoa, a week before its official launch. The restaurant is in an enviable spot on Piccadilly itself, just next door to the home of BAFTA and conveniently close to No.3 St James’s Street. Heavy doors open onto a luxe-look restaurant; a touch of Old World, art-deco glamour with modern lines. Oliver is enthused about the site, “I love the area; I sort of never thought we’d be here,” he says. And it’s taken a while: he has been trying to open here for four years. “We had some ‘challenging building complications’, shall we say. So, in some respects, not great, because we’ve been geared up for it for five years, give or take; but then sometimes you have to wait for a peach.”

It’s 18 years since the Naked Chef first appeared on TV, and his non-profit project, Fifteen, turns 15 this November. “Fifteen years in London feels like quite a long time,” he says, considering how Hoxton has developed, within that time, from a “s***hole” to somewhere few people can afford to live; and how the restaurant itself has gone from being “the coolest thing in town” to questioning its place and purpose. Despite this, he feels Fifteen has “never been in a better place”.

For now, though, his focus is on the long-awaited Barbecoa II. He’s frank in his description of it as a “steakhouse”, albeit a really good one: “Ultimately it’s about amazing grass-fed beef, lamb and game.”

The Piccadilly branch is not, however, an identical twin to the original St Paul’s eatery which opened in 2010. “Barbecoa I is super fly, bling and – dare I say it – a bit more Essex,” Jamie explains. “Kind of Barbarella on steroids in a spaceship that’s landed next to St Paul’s. And it’s great. I don’t know any other restaurant like it, and it still looks cool. Tom Dixon did a great job. But this is a very different kettle of fish, a bit more grown up. You can hear conversations a little bit easier. I think we felt we’d be catering for a slightly older demographic, and that’s probably fair. But ultimately the food’s very straightforward, the ingredients are very good. We’re possibly trying to show a bit more restraint. And I like that.”

He is clearly conscious of the current climate, with a saturated restaurant market, and the need to ensure his offering is better than anyone else’s. It’s one of the reasons the new site is serving breakfast and afternoon tea. “Just having one trick is possibly not good enough for most people these days,” he says. “Having excuses for people to love you and trying to be good at loving them back is probably what you need. It’s a rough old industry if you get it wrong. And we don’t want to get it wrong.”

An important element of this is “a legit bar”, he says. Only in the past four or five years has there been an intention to build bars that were objects of beauty in their own right, a centrepiece for his restaurants. At Barbecoa II, he says, “it’s big and beautiful, and when there’s four or five bartenders behind there rattling it out, you know it’s going to look great.”

This is, he suggests, reflective of the changing attitudes to food and drink, with the last 30 years bringing the two closer together. Historically, he says, Britain was “a nation of drinkers that went and got some grub with the munchies on the way home”; today, though, things are rather different. And he has played no small part in changing them – engaging with and educating an audience about food.

It’s easy, as he says, for “the wet side of the business” to be forgotten by chefs (if well appreciated by them at the end of the day); but it’s an important part of the industry. Since 2014 he has been running Drinks Tube, a YouTube channel with videos on wine, beer and spirits, and a particular focus on cocktails – the category that he feels is the perfect “bridge” between food and drink.

As my allotted time runs out, and the next item on the schedule steals Jamie’s focus, I can’t help but be impressed by his utter indefatigability and total normality. There are over 30 restaurants just in the Jamie’s Italian chain, he has 22 cook books to his name and has appeared in almost 30 television series, not to mention his five children or MBE for services to the hospitality industry.

Oliver’s influence on the way we eat, at home, at school and in restaurants, is indisputable; yet somehow he comes across as totally down-to-earth.  Unstuffy and unstoppable, he isn’t running out of excuses for us to love him yet. And he really does seem to love us back.

Barbecoa Piccadilly is now open; find out more and book a table here.