If it were up to me, the phrase ‘I don’t eat fish,’ wouldn’t exist. Don’t get me wrong, I’m not including those who are genuinely allergic, who are obviously exempt – or those who choose not to eat any living creature, which I’ll very happily accept depending on the way they make their argument.

I’m talking about adult human beings, of relative means, who have had the opportunity to taste a decent amount of the edible provisions from the thing that covers almost three quarters of the Earth’s surface, and have been a staple diet of hundreds of millions of people for the majority of human history, and have decided they don’t like them. For something so bountiful, varied, occasionally confounding but so frequently delicious, the fruits of the sea are still – even among the relatively food-literate – something that’s actively avoided by a not inconsiderable number of people.

I’ve eaten fish and seafood at many restaurants and in many forms, from the humble to the elevated and beyond. Sardines right off the grill in Matsusinhos in Portugal, served with a squeeze of lemon and a pool of verdant olive oil, is a simple but powerful and elemental treat. Sea cucumber carbonara at Etoneca Paco Pérez in Barcelona or tuna belly ham at Ricard Camarena in Valencia, is probably considered to be the other side of the scale. There are many that love the former, and wouldn’t get on with the latter, and that’s fine. But I love it all.

My best friend does, too, which is why the thought of descending on Mayfair to a new seafood-focused restaurant helmed by a chef of some repute is an exciting one. So in early January, that’s what we do.

Mazarine
Mazarine

Restaurateurs Khaled Dandachi and Fred Srouchi were the minds behind importing the excellent (and dare I say underrated Sparrow Italia) to a street less than a mile away, and for Mazarine they recruited Thierry Laborde, former head chef at Le Gavroche and also La Petite Maison, to head up the kitchen’s operations.

The brief must have been a fun one, too: a seafood-centric menu, adventurous without being alienating, and an experience and setting that justify their plush surroundings while also standing out from the crowd.

The room, created with help from American firm Bolt Design, aims to do just that. Its floaty, wavey, undulating décor recalls snorkelling among sand banks on the way to a coral reef – a deliberate play, of course, given the focus of the menu. It manages to be soft but crisp, understated and unpretentious but still design-led, conceptual and modern. Check.

But back to the food, and if my mention of very out-there seafood has you slightly apprehensive, don’t worry: things aren’t too conceptual at Mazarine – at least not compared to those aforementioned two-Michelin-starred venues. Here, fine-dining preparation and plating is definitely on the agenda – thanks in part to its chef and his extensive experience in this neck of the woods – but short of grilled sea urchin, there’s nothing on the menu a reasonably well-travelled diner won’t have come across before.

What you will get is a pan-European selection of market-fresh fish from an extensive à la carte menu of often exquisite but usually straightforward dishes. There is nothing deliberately cheffy going on here, but there is playfulness: fresh sardine, like a breath of the sea, is amped up with the umami of sun-dried tomato and black olive in a starter; a smoked eel and potato croquette is delicate, texturally balanced and resists leaning too far into its hero ingredient’s potential for overwhelming punch. Caviar appears, but used judiciously with a fantastic fried brioche starter, and there’s a great octopus carpaccio, too.

Seabass at Mazarine

The wine list bears the same accent as the food, and while we don’t set out for an all-French flight, we fall into it naturally. A Premier Cru Chablis from Les Hauts de Milly pings off the palate with all the bracing edge and fine minerality you’d expect, while a 2022 Rully – an underrated and often underpriced Burgundy appellation – from Jean-Baptiste Ponsot has obliging lactic creaminess and toasted oak in addition to its fruit.

Sauternes from Château Laville has tropical fruit in abundance, and just a hint of sweet riesling-style tennis ball (trust me, it’s not an off note).

The first courses are probably the most fun, but the mains are there to deliver for an audience that knows what they like and how they like it, and they duly do so.

Beautiful cod comes atop a pil pil sauce, a classic Basque preparation that sees the fish’s cooking juices emulsified with olive oil, and with a few grilled padrón peppers on the plate for bite and balance.

And the true main event is in its presentation as much as its flavour: a huge baked sea bass that’s brought to the table in its salt crust and served as we watch. It’s expertly deboned, but beyond that the fanfare is left to the guéridon service, and the fish itself – robust in texture, delicate in flavour, juicy and delicious – is served simply with lemon.

So yes, you’re not going to like Mazarine if you’re one of those people who claim they ‘don’t like fish’. But if you do, you’re probably going to really like it – it turns out giving an ex-Gavroche chef the keys to a temple of approachable but superbly sourced seafood results in something very good indeed.

22 Hanover Square, London W1S 1JA; mazarinerestaurant.com