He’s not the first to have found he thrives in both settings. Gordon Ramsay was also a pro footballer before making the switch, while Frantzén reveals that, “most of the people working both front of house and kitchen in my three-Michelin-star restaurants have a very serious athletic background. It’s a competitive environment. And you need to like to have that pressure, otherwise that pressure will eat you up”. 

After completing a tough stint of national service in the far north of Sweden, the 20-year-old Frantzén got himself a job in a Michelin-star restaurant, Edsbacka Krog, near his home in Stockholm, before travelling to England and working at Le Manoir aux Quat’Saisons, cooking under Raymond Blanc. And he ended up staying in the UK for six years, moving on to work with Nico Ladenis at 90 Park Lane and Tom Aikens at Pied à Terre. 

Heavily influenced by French cuisine, he then decided to go to the source, digging in for seven years of hard graft in two- and three-Michelin-star restaurants in France. But he yearned to open his own restaurant – and to earn some of those much-coveted stars of his own. “I worked so, so hard,” he recalls, “so I didn’t want to go and work as someone else’s head chef and give away all my ideas. I wanted to try to do it on my own.” With his sights firmly set, he returned to Sweden, where, by his own admission he was “young, fearless and cocky… you need to be that”. It was just as well: the process was not easy, and with no investors or family money, it took three years to get the funding from the bank, using his apartment as security on the loan. 

With everything on the line, the restaurant, Frantzén/Lindeberg – a joint project with pastry chef Daniel Lindeberg, whom Frantzén had met at Edsbacka Krog – opened its doors in 2008, the point at which the world was at the peak of the molecular gastronomy craze. The instigator of that was Spanish restaurant El Bulli, regularly voted The World’s Best Restaurant, and for the first few months, the chefs at Frantzén/Lindeberg focused on the El Bulli style. But change was in the air. Chefs including Noma’s René Redzepi had signed ‘The New Nordic Food Manifesto’ in 2004, committing to seasonality, locality, ethical food production, health and the promotion of Nordic tradition. As Noma climbed the World’s 50 Best Restaurants list, spherification, hot jellies and foams – while still entrancing diners at El Bulli – were beginning to seem rather old hat to those at the forefront of the food world. 

Ingredients, not techniques, were now poised to become the driving forces behind menus. Within months, Frantzén started a collaboration with a market garden outside Stockholm, and the quality of vegetables arriving at the restaurant made the chef revisit his approach: “I didn’t want people to talk about the liquorice air that was served with the onions. I wanted them to speak about the onions, because there was so much work put into these ingredients.” 

The pivot in style paid off: within a year, the restaurant had been awarded one Michelin star. A second star arrived a year later, and Frantzén/Lindeberg was accorded ‘One to Watch’ status by The World’s 50 Best Restaurants. In 2018 – five years after Lindeberg had left the partnership – Frantzén won its third star; that same year, Zén opened in Singapore; and now, the spotlight falls on London, heralding a return that Frantzén has dreamed of for a while. “The UK was my home for a long time,” he says. “I love London. And the Swedish and British have the same sick sense of humour!” 

As a child, when he came to the capital, he was staggered by the city’s size and dynamism. Now, he says, “It’s overwhelming to come back to open a restaurant in my own name in London. It sums up my career, and I’m proud of it.” It couldn’t be just any old restaurant though. Over the years, Frantzén has rejected many offers to come to London; Harrods, however, he couldn’t turn down. “Everybody knows Harrods. It’s a world-famous brand,” he says, clearly relishing the association. Conventional spaces are not for him either, he adds. “I love the location right up at the top, and it’s the only rooftop terrace in Mayfair and Knightsbridge.”

The Studio Frantzén menu will be a simplified version of the food served at Frantzén, suitable for a couple who want something light at 2pm as well as “people dressing up big time in the evening”. But, he says, “Diners will definitely recognise similarities if you have been to the other restaurants.” In keeping with the Nordic principles, ingredients will be mostly local – Frantzén is a big admirer of British dairy, seafood and lamb, in particular – with Scandinavian and Japanese flavourings, so visitors can look forward to a signature dish of steamed turbot with Jansson’s temptation as well as shio-koji-marinated whole chicken.