There's a sense in the London food and drink industry that 2020 is probably not the time to gamble with a new opening. And while the boom time that lasted a decade or so after the financial crash of 2008 – when new restaurants had to be actually dreadful not to see eager diners flock to their doors – seemed to be coming to the end of its cycle, the repeated hammerblows of Covid-19 have accelerated that fact drastically. Put simply, if you're opening a restaurant in mid-2020, amid the spectre of lockdown, it had better be a sure thing.

Or not, as the case may be. Following expansion from his native Glasgow to Edinburgh, Belfast, Manchester and Liverpool, Nico Simeone's move into London comes at exactly this time, and while the elevator pitch is catchy (six courses, £6 each, and a menu that rotates every six weeks) it still seems like a concept-first restaurant – and therefore, possibly, a big gamble.

The location is bold, too. Charlotte Street is not exactly lacking in top-quality fine-dining restaurants: here, big hitters like Jun Tanaka's The Ninth and James Knappett's Kitchen Table (a two-Michelin-starred counter dining experience hidden inside Sandia Chang's more casual Bubbledogs) mingle with London royalty like ROKA and Pied à Terre. Opening here is ballsy, but the evidence suggests that Simeone has the chops to make it work. His tasting menu is fun, gimmicky by design, and a genuine snip at £36 a head for six courses. It's definitely fine dining in look and feel, and although you might find more refinement in the food and service of the aforementioned venues, you'll also pay a decent amount more for it.

Six by Nico London's opening menu was named 'The Chippie'. An ode to British fish and chip shops, it featured dishes like 'Fish Supper' – Shetland cod with confit fennel, samphire beer emulsion and pickled mussels – and a version of a deep-fried Mars bar (he is Glaswegian, after all) made with chocolate, chocolate mousse, blood orange sorbet and cocoa nib. But his sophomore menu benefits from a broader approach. Named simply 'Childhood', it comprises a series of dishes that are meant to recall gleeful nostalgia of eating as a child in Britain.

From the off, the aperitif is playful – made with orange soda, orange liqueur and emulsified 'ice cream', it tastes like a boozy Orangina float, though perhaps Simeone misses a trick not serving it with a straw made of uncooked pasta, that childhood staple of bored Saturday afternoons, to slurp it through.

The supplemental canapé is a beef burger 'doughnut', with a piping of house ketchup and mayonnaise, which features good texture and old-favourite flavours: the punch of gherkin and the unique flavour that only occurs when those condiments mix atop minced beef. A broken-down lasagne is next, and is delicious in the simplest of ways: ox cheek is just firm enough, with bite, a puffed fried pasta sheet adds crunch, and the espuma is jaw-stingingly cheddary. I was told off by my fiancée for running a finger through the rest of it after the last forkful – although surely, I argued, that should be encouraged here.

'Fish Finger' at Six by Nico London
'Egg and Soldiers' at Six by Nico London
'Mac n' Cheese' at Six by Nico London
'Duck Duck Goose' at Six by Nico London

While the approach here entails Great British Menu levels of overt creativity, some of the dishes are direct references, and some use their names merely as a loose jumping-off point. The 'Fish Finger' – a salmon tartare with a dulse seaweed cracker, kohlrabi, lime gel and dressing – is rectangular, and made of fish, though the similarity ends there. But it's peppery and saline, and an excellent dish that shows an eye for classic French cooking among the gimmicks.

'Mac n' Cheese' is a highlight, although the titular snack actually takes a back seat here to a sumptuous cheddar cannoli, roasted cauliflower, and a vinegary raisin and caper purée and truffle sauce, with fresh grape to cut through its dirty, toe-curling deliciousness; while 'Egg and Soldiers' is a half of a breaded, soft-boiled egg served with celeriac and lovage gel, a slick of punchy sauce and dehydrated herbs with an apple and kohlrabi slaw.

'Duck Duck Goose' is as close to Simeone gets to classic Franco-British cooking: a seared and roasted duck breast, a Christmas-spiced bonbon of confit leg meat, just-fried gnocchi and a gamey jus. While the dish plays it relatively safe, I can't help but notice the four guys on the table across from me talking about playing the game as kids, and in that sense, it nails the brief. As, in a different way, does a dessert dish that my fiancée says actually tastes like its namesake dessert 'Ring o' Roses', with a soaked biscuit, tart berries and a sweet custard, served alongside a Lambrusco-style brachetto, full of bramble fruit notes and brioche.

Speaking of which, an extra £30 or so for the paired flight is good value – wines here aren't super-premium and are served in uniform, chunky glassware, but there are some out-there choices. That brachetto is one, as is a natural Tea Leaf White Blend from The Strange Kompanjie in Piekenierskloof, South Africa, a mix of aromatic white grapes so-called because they're grown in amongst a rooibos plantation. There are some safer (and less exciting) bets, like a Beaujolais Villages, all strawberry fromage frais on the nose, alongside the duck course, and a half-decent Languedoc rosé earlier on.

Overall, though, the quality on show – and the packed dining room in which the action unfolds – is a timely reminder of an encouraging truth: that even in dark times, with a very real threat hanging over the hospitality industry, playing it safe isn't the be-all and end-all. The fact remains: whether you're hawking bao buns at an outdoor market or creating conceptual tasting menus in Charlotte Street – if you build it, and it's good enough, they will come.

'Childhood' runs until 18 October. 41 Charlotte Street, London, W1T 1RR;