The Seafood Bar, 77 Dean Street, London W1D 3SH (020 4525 0733). Starters £9.50-£12.50, mains £15.50-£32.50, platters £27.50-£49.50, desserts £6.95-£7.50, wines from £25

It starts badly; terribly, terribly badly. We order the calamari, a sizeable plateful at a sizeable price of £10.50. It is very much old school: a pile of those hefty rings of golden battered mature squid that the British came to associate with the sun-kissed exotica of 1980s Mediterranean holidays. Sangria, sunburn, the glamour of deep-fried calamari. I merely have to glance at them and soft waves of nostalgia wash over me. I can almost smell the Nivea After Sun.

Now I bite in and what comes away with the meaty ring is a slippery spittle-thread of something sickly white and troubling. The squid hasn’t been de-membraned before being battered and deep-fried. It looks as if it’s producing dribbles that need to be wiped up with a tissue. It’s cack-handed and a terrible waste. The newly opened Seafood Bar on London’s Dean Street makes a lot of noise about the sustainability of its business in general and the ingredients it uses in particular. But there’s no point bigging up your ethics if you’re not going to attend to the essentials.

Happily, it turns out to be an aberration, because we will eventually get to our main courses and they will be magnificent. They will more than make the case for the restaurant’s recent opening. Which is good, because I was beginning to wonder whether it had a hope in hell of surviving. The Seafood Bar is the first British outpost of a Dutch restaurant group, with four branches in the Netherlands. It occupies the home of what was once the Red Fort, a venerable Indian restaurant much beloved in its pomp by Labour party bigwigs because of the support given to their cause by its owner, Amin Ali.

I had never clocked before just how big the Red Fort site was. Now it’s been stripped back and you can see everything. There’s white tiling and white slat-board frontages to the bar. There are flourishes of beige, if beige can flourish, courtesy of pale banquettes and blond-wood flooring. There’s also a little bare brick illuminated by outbreaks of neon signage. It looks like the decor has been done by a subsidiary of the White Company, in an attempt to break out from all the bed linen and towelling. For weeks I’ve been able to see all this through the huge front plateglass windows because, every time I’ve passed, it has seemed remarkably empty. As in, people kept remarking to me on its emptiness.

The issue, I think, is knowing what the Seafood Bar is for, because all successful restaurants need a clear purpose. There’s the date-night place, and the special occasion place; the family supper place and the “can’t be bothered to cook” place. In Bentley’s, Scott’s and J Sheekey, London already has three big-ticket seafood gastro palaces. Close your eyes as you hand over the plastic and intone the mantra: “Good seafood should never be cheap.” Somewhere in the mid-market there’s Parsons and Bob’s Lobster, Oystermen and the various Wright Brothers. No, none of them are exactly cheap, but you will probably escape without flogging a kidney.

So what of the Seafood Bar? What’s it for? After all, the menu includes a fruits de mer for two at £87.50. That puts it firmly in Sheekey territory, doesn’t it? This is where it gets interesting. It is most definitely about seafood platters for sharing. The thing is, the sharing might not quite be in the way the restaurant itself intended. I am aware that what I’m about to say might undermine their business model, but as this is what I’d tell a close friend, I really ought to tell you this, too.

Their platters for one are enough to feed two. Let’s start with their “mixed grill from the plancha”. What they call a serving for one costs £35 and includes a huge king prawn, big fat shrimps and rings of (happily de-membraned) squid, a thick piece of salmon, a few slip sole fillets and a good-sized sea bass fillet. Oh, and half a lobster. All of this comes in a ripe tomato sauce at the bottom, and is dribbled in places with herb garlic butter. Finally, it is decorated with fronds of samphire. Get a bowl of their very good chips each and an awful lot of napkins, and you will both be sorted. It’s immense.

Exactly the same applies with the fruits de mer. There is a version for one at £49.50, but if you’re willing to forgo the lobster, it costs £27.50. And again, there’s an awful lot for your money. There are mussels and razor clams, cockles and brown shrimps, periwinkles, prawns, clams and a langoustine. There’s a seafood salad plus rolls of smoked salmon, a hunk of brown crab, a seaweed salad and a couple of rock oysters. There’s a bowl of a Marie Rose sauce and another of a herb dip. There’s a whole lot of everything. You get the idea by now: a portion or two of chips, some salad and the job is done. Come here if you need to get into the nitty gritty of life with a close friend, or even just with a mere acquaintance. It is impossible to be formal with anyone when you are up to your armpits in shellfish debris.

The menu has other things. There’s a sea bass ceviche, which is serviceable. As mentioned, they make a lot on their website about the sustainability of their ingredients including the salmon, Nordic Blu, which they say is the most sustainable farmed salmon in the world. If you care about this stuff, and you should, you can read all about it for yourself on their website.

There are just two desserts: a multilayered chocolate mousse and a cheesecake. I take one look at them and know immediately they weren’t made here. Our chatty and knowledgable waiter confirms this. Don’t let those detain you. You’re in Soho. The great Maison Bertaux, which has been doing its fabulous cream cake and patisserie thing since 1871, is only over on Greek Street. Just at the bottom of Dean Street is Maître Choux, for some seriously impressive chocolate eclair and choux bun action. You have better choices. But do come for those seafood platters. I will simply have to keep my fingers crossed that they don’t now rethink their portion sizes and prices as a result of what I’ve said. Because what they’re offering deserves a good crowd.

News bites

Chef Niall Keating of the multi-starred Whatley Manor in Wiltshire is overseeing the menu at a new restaurant launching next month in his home county of Staffordshire. Lunar will open on the site of Wedgwood in Barlaston near Stoke-on-Trent, and is named after the famed Lunar Society, part of the Midlands enlightenment, of which Josiah Wedgwood was a founding member. The Asian-inflected menu will feature small plates including scallop with citrus and preserved ginger, and tempura pumpkin with tamarind and chilli as well as sharing dishes like clay baked chicken with treasure rice. Visit lunarwedgwood.com.

The ever-reliable Great Taste Awards, which hands out up to three stars to products across a broad range of food categories, have announced their supreme champion for 2021. It’s the oak-smoked Mallaig kippers from J Lawrie & Sons in the Scottish Highlands. The judges praised them for their ‘perfect balance of wood, smoke and fish’. Those award winners are available to buy online alongside their other smoked fish products at jaffys.co.uk.

Shoryu Ramen, which operates 12 sites across London, is launching a franchising model to extend the brand across the rest of the UK. The company, which suspended its franchising plans in 2020 when the pandemic hit, is looking for single and multi-unit franchisees immediately. See shoryuramen.com.

Email Jay at jay.rayner@observer.co.uk or follow him on Twitter @jayrayner1