Selfridges, 400 Oxford St, London W1A 1AB

In the Fragrance department of Selfridges, a dedicated express lift is waiting to swoop you up to sun-filled heaven on the fifth floor.

While most large London buildings have their rooftops closed to the public and cluttered with aircon units, Selfridges have been making the most of their roof as a very unique dining destination for some time now.

Latest to get up there is alto by San Carlo. Leaving the express lift on the fifth floor you get to walk through a rather charming evergreen walkway, which usefully hides the more prosaic service corridor the walkway really is, before arriving at the steps up to the restaurant itself.

It’s a revelation as you emerge into the daylight. The restaurant stretches away with the view of London’s skyline to the left and a charming faux Italian exterior to the right and a retractable roof to outwit the English weather.

The place is buzzing this lunchtime with lots of elegant people and rings cheerfully to the sound of glasses being brought together and cutlery being enthusiastically wielded.

Staff are rather formally dressed, which is rather a nice touch, but they are not formal in manner just cheerful and accommodating.

A bowl of glossily fat green and black olives, plus another of nibbly smoked almonds keeps me busy while checking out the large menu, as well as the seasonal section.

Pastas, pizzas, fish, meat, salads,Josper Grill specials; it’s all there and all dishes are designed for sharing. In fact, a waiter utters the immortal phrase’Italian tapas’, but I shudder inwardly and pretend not to hear and instead order an Aperol spritz as, even though the sun isn’t coming down quite full force, it’s still a hot and muggy day.

Soon ice is clinking and all is well. I could almost be in Italy. Kicking off with gnocco fritto and prosciutto I’m a bit disappointed to find the gnocco aren’t the air-filled pillows of fried flour, yeast and lard I expected and always eat in Bologna, but instead long, rather heavier versions.

Each region does them a bit differently, it appears. Anyway, they still taste good when enrobed with a slice of quality prosciutto. Saltiness and fried fats, you can’t beat it.

Still on a frying theme there’s a plate of mozzarella in carrozza – buffalo mozzarella fried in breadcrumbs with a pesto sauce. The pesto is the star here, bringing out the mozzarella’s creamy flavours and cutting the fried texture just right.

I start to feel a little overloaded all the same, maybe I am having too much from the fryer? It’s hard to resist it, but the penalties on the waistline from fried food are as inevitable as a penalty shoot-out at a World Cup Final – a heavy feeling and some remorse.

Pizza or pasta? I do like a pizza but I prefer pasta, it seems somehow more suitable for a summer’s day.

I’m always keen to try a different pasta dish too and paccheri with prawns, mussels, garlic and chilli is a slightly new one on me. Paccheri, it turns out are large tubes of pasta, these slightly on the hard side of al dente but just about getting away with it.

The chilli buzzes through gently but insistently, while the mussels are plump with just the odd grind of grit that has got through the prep process. It’s a dish that makes me wistful for a sea breeze and that peculiar, almost Alpine, clonking sound that moored yachts make as their ropes knock against the steel masts.

Fillet of Salmon, chargrilled with cannellini beans, sun-dried tomato and cabbage is a bit of a winner, if a bit of a surprise. I’d not think to partner beans with salmon myself, but then again it does work with tuna so why not?

In any case, we’re not talking a hill of beans here, just a small handful decoratively tumbled about (I am getting the hang of using Nigella verbs), along with the tomatoes and cabbage, so the salmon remains the star of the show.

A thick fillet, not bearing any obvious scars from grilling actually, but butter soft and slightly smoky and with a crispy skin. Personally, I’d have cooked it a fraction less, I like the center’rare’ to contrast with the exterior, but nothing to complain about.

Good meaty forkfuls enlivened by the powerful tomatoes and given textural variety by the beans. The latter I’d say have been prepared from dried, as they don’t have the slight sliminess that tinned ones tend to exhibit, so bonus points there.

Finish off the wine, a decent white from Abruzzo, and then a good old pannacotta is called for. Wonderfully wobbly, the pannacotta, not me, and drizzled with a rich strawberry reduction this is just what I like to eat and I don’t often eat desserts. Quite a large portion too, which is not always the case, sadly.

It’s a big menu at Alto, as I said, and that can be a concern. Few kitchens can do everything well, but they seem to be hitting it at above average here, which is no mean feat.Prices are pretty fair too considering the location and the elevation.

You can also sit outside too which makes it perhaps the only outside restaurant seating in London that may not come with a side order of air pollution, I mean five floors should be alto enough to be above the worst of it?