Nestled between grey buildings, just behind Oxford Street, is a plant-based burger restaurant. It might look unassuming – a white shop front with a small logo, a few turquoise tables and chairs outside on a tiled patio – but Neat Burger promises delicious food that’s been backed by Lewis Hamilton, among several other ultra-famous celebrities.

Step inside and you’ll find the Instagrammable décor of your wildest dreams. Metal palm leaves stand proudly above seats on shiny white tiles. Bar stools surround the perimeter, so you have the choice of people-watching or watching yourself eat. The service counter has a white neon logo behind it, and when you turn around there’s a pink rotary-dial phone, complete with yet another neon sign, pink this time, that reads “I plant get you out of my head”.

Despite the menu’s small size, I initially struggled to decide what I wanted to try. I ended up ordering a “chicken” burger with some tater tots, both drizzled in vegan cheese: the kind server behind the counter recommended the cheese, telling me with a grin that it was “sensational”. I initially assumed she might have been overselling the cheese, but I was glad to be proved wrong.

A short wait later, my food was ready, as promised with vegan cheese, an almost luminous orange, covering it all. It looked absolutely amazing, served in adorable pastel (recyclable) packaging on a tray. Just from looking, the food was really well-prepared, with not a hint of grease in sight – just what I’d wanted.

My first bite was pretty average. The burger bun itself was delicious and served as a distraction, but the “chicken” felt a bit rubbery. The fact that the burgers are made from mushrooms was disappointingly obvious.

I’ve always found vegan cheese to taste disgusting, so I had very low expectations for it. If not done correctly it tastes like it’s out of date. But this is where I was surprised; in the burger, the cheese was tasty, and wasn’t overly strong: any stronger and it would’ve overpowered everything else in a bad way. Maybe it was the sheer volume of it I ate, but the tater tots would have been miles better if they were cheeseless – but they were still pretty delicious.

The true star of the menu, though, is the milkshakes; the salted caramel was so incredibly creamy that it made me worry it contained milk. But I was assured at the counter that no milk products were anywhere on the premises, so milk allergy sufferers can dine at Neat Burger in peace. The beautiful caramel flavour of the milkshake, with a drizzle of caramel syrup on top, made the journey to London’s busiest street worthwhile.

Neat Burger’s offerings are still up there in the rankings of some of the best vegan food I’ve tried, even if I was left slightly disappointed. If they introduce a vegetable burger, I think their popularity will shoot up to even more stratospheric heights – but for now, their fake meat offerings do a pretty good job of masquerading as the real thing. And the tater tots are pretty brilliant, too.

A meal for two at Neat Burger (Mayfair) costs around £30. 3/5 stars