A Flair For Grills At London's 34 Mayfair

Just off the edge of quintessentially British, carefully manicured lawns of Grosvenor Square, 34 Mayfair's exterior is festooned with floral canopies, while inside is a surprisingly intimate, wood-lined, leather-seated diner. This might be a grill house but the dress code is smart, with crisp ironed shirts the garb of choice. It all feels very Upper East Side, the Brit edition. It's part of the Ivy, Le Caprice, Sexy Fish and J Sheekey group, so there's a expectation that this will measure up. Not being as well known as its siblings allows it a certain intimacy and privacy. Apparently it's a favourite of the Duchess of Cornwall, Camilla Parker Bowles.

With seasonal asparagus on the menu during our visit, we plumped for what proved to be stupendous starters, the delicate flavour subtly charred and sweet, and the new summer menu offers Aparagus soup and butterleaf and avocado salad in a tomato and champagne dressing, which promise to be as good. If you feel like some caviar that's also an option.

For mains it's all about the bespoke Argentine parrilla grill, the centrepiece of Head Chef's Harvey Ayliffe menu, with pure heritage breeds from the Yorkshire Dales and A5 Japanese Wagyu. My companion chose the fish of the day, halibut, which was succulent, flavoursome and delicious with a heap of perfect spinach and decadent creamy hollandaise sauce all pairing impeccably. I wanted to see how things were off the grill, so tried tuna with noodles. My friend, who had eaten here before said, aghast at my choice, 'but it's a grill'? He was right – tuna was silky and immaculately cooked – grilled, I might add – to just the right amount of rareness in a milky hued broth, with udon but it nonetheless paled compared to the beautifully cooked simplicity of the slabs being ushered out from the busy open kitchen.

Pondering excitably over the desserts we were torn but eventually eschew the raspberry and lemon millefieulle for Liberty Garden of Beauty, which is a good call as it's the most beautiful pudding I've ever seen – a liberty cushion of cherry and rose mousse topped by white chocolate – and it even matches the upholstery.

For a classy but relaxed-feeling lunch in Mayfair this can't be beat, just don't forget a nicely pressed shirt and to order wonders from the grill. And leave room for a perfectly coordinated dessert.