Though his restaurants have a shared spirit, over the last few years Tomos has drawn a distinction between the dishes which belong at Brat and those which call Mountain home. Already becoming a Mountain signature (its version of Brat's whole turbot, a dish with which it has become synonymous and which inspired its name; Brat is an old English nickname for turbot and also means apron in Welsh), the whole lobster caldereta is a good example, Tomos says. A traditional Minorcan stew, it's a rich, hearty dish ideal for messily tucking into with loved ones, and one which needs the right environment to shine.

‘The braised lobster dish was formed on our travels to northern Spain and Catalan and inspired by the Welsh abundance of lobster,’ he says. ‘I guess it’s become a bit of a signature dish, and it requires a lot more time and space – it’s a two-day process to make the sauce, so it can only be done at Mountain. Mountain’s dishes are a different kind of expression of northern Spain. I feel that this restaurant is way closer to my Welsh heritage, because lots of the dishes in Wales are braised; there’s a very famous cawl called lobscouse, which is a braised mutton dish and probably the most famous Welsh dish. These dishes feel really soulful for me. The Brat ones are more like the produce from the farm, from the sea, grilled and sent out – I guess there’s a little bit more tradition in the dishes at Mountain, essentially.’

Spain’s Basque region has always underpinned Tomos’ cooking, though his appreciation of the area goes beyond its cooking. ‘It’s this remarkable comparison of the area to Wales and where I grew up,’ he nods. ‘When you go to the Basque country, if you were to get dropped there, you could think you were in Wales and vice versa. There’s a big connection between the countries – like the Basque country sees itself quite independently from mainland Spain, the same as in Wales with England. It’s not so much like anti-English or anti-Spanish, it’s just because they are unique in themselves.’ Other similarities around landscape, language and history (Tomos studied a History and Politics degree at university) have only deepened that respect. 'During the Spanish civil war, a lot of Basque people were taken in by the Welsh as refugees,’ Tomos explains. 'There’s this strong connection between the communities, which I always felt, and I loved their style of cooking – it really appealed to me.'

Tomos moved from Cardiff to London at twenty-five, landing a role at The River Café and staging at Noma, where he met James Knappett, who he later helped to open Kitchen Table. He began barbecuing at Climpson’s Arch in Hackney, fine-tuning his skill with a wood-fire grill. It was there that he met the owners of Kitty Fisher’s – an Anglo-Spanish restaurant in Mayfair – who were so impressed by his cooking that they soon offered his a job, his first head chef role. Tomos later went solo, opening Brat in 2018, and, well, you know the rest. Five years ago, though, when Tomos was first going it alone, could he have predicted its success? ‘When I put my soul and passion into something, I’d hoped that people would enjoy the product at the end, but I never thought we’d get these accolades,’ he smiles. ‘It’s so lovely that people like it, and I think it’s always, with these things, a matter of a great product and a talented team, but also time and place, you know? It could have been that the market was really calling out for something like that. You never quite know, but I always think it is an element of time and place combined with skill and expertise.’

There were probably few who feared that Mountain would have a quiet first few weeks, but Brat's enormous success and the lofty expectations it created could certainly have been a double-edged sword. ‘There’s definitely lots of pressure,’ Tomos says. ‘Soho is a huge investment not only financially, but mentally. You just never know.’ Though Mountain's first flurry of reviews have been glowing and accolades may well be on the horizon, Tomos is focusing on a different measure of success. ‘Longevity is something that’s super exciting for me,’ he nods. ‘I’d love to be sitting there in a similar breath to The River Cafe, or St John. What we contribute to the London scene is really important to me. If accolades come, that’s great, but they’re not the main driver – I would love to have a load of people who worked with us go on and open other restaurants and have that feeling that they contributed to the scene and supply chain.’

Building a legacy that lasts is no easy feat, and nor is weathering the turbulence unseating so many restaurants. So, how does Tomos hope to forge an enduring appeal? 'The River Café, for example, is kind of an institution now, but at its core the values are incredibly strong,' he says. 'You know, source well, treat your team well, be quite progressive. I think core values are really important – that’s what we try to keep. It’s not going to be everyone’s taste, that’s just the way the world works. But if you are true to your core values, I think it gives you longevity.’