Cocktails are funny things – get them wrong and they’re simply an overpriced waste of some perfectly adequate booze. Get them right though, and you can have something truly wonderful on your hands. Well I’m happy to say that the recently launched cocktail bar at Flemings Hotel, Mayfair is doing something very, very right.

The décor may not be to everyone’s tastes – all theatrical turquoise, amethyst, jet and jade tones, with plenty of mirroring, bold lines and shapes – but it’s certainly comfortable: the kind of place that provides a camp little sanctum from rush hour’s belligerent bustle. The menu is similarly idiosyncratic: it tempts you to “enter the secret garden”, where the drinks are “luscious”, “voluptuous”, or “served straight up for your pleasure”.

While we’re there – we being the founder of the New London Cocktail Review, Kina Lillett, and I – we’re looked after by the brilliantly helpful Colin Exton, Director of Hotel Sales, whose baby this theatrically revamped bar so evidently is. We’re served a selection of quite fantastic canapés – an artichoke and prosciutto concoction is a highlight, alongside a slice of smoked salmon, humming with truffle oil.

But the drinks, the drinks! Well, they say the best way to really test a cocktail bar is to order the simple and the classic. That way, no amount of umbrellas, fruit, dry ice or sundry other extravagances can distract one from the matter at hand. In short, there is nowhere to hide. Bearing this in mind, Kina goes for a dry gin Martini – they use Sipsmith gin, we’re informed, and it shows. This is a seriously classy drink – punchy, but smooth, just as it should be. It’s boozy as hell but with none of the grit or grime that even quite good makers of the drink somehow can’t seem to avoid.

We order two other cocktails (house specials) which were also very good – although in truth I can’t remember more than that. What I can remember (and probably will never forget) is that the real show stealer is my Negroni. I’ve elsewhere described the ideal Negroni as “crisp, bitter and persistently ginny” and this, well, this is exactly that. Served in an elegantly hefty William Yeoward tumbler, this Negroni positively zings with medicinal booziness. And yet, its balance and poise are really quite exceptional. I’m often accused of hyperbole, but genuinely, this, and I’ll lay down the gauntlet here, is the finest Negroni in all of London. Here’s a challenge to every bar in town: make me a better one, and I’ll…I’ll…well, I’ll drink it. That’s what I’ll do.

www.flemings-mayfair.co.uk