One Square doesn’t answer its phone. Sitting here now in this joyless restaurant I realise that I should have taken that as a warning that the Sheraton doesn’t expect anyone who isn’t resident or doing business in the hotel to eat here. The diners here this evening- very few, maybe the bad word has got around- are corporate, all men. Their companies will pick up the bill, I expect, never a state of affairs that begets good food.

I’m here because One Square has a new chef. You certainly wouldn’t come for the experience. Although the restaurant is almost empty we’re sat at a cramped window table. Normally you’d want a window table. Theoretically speaking, this could have a phenomenal view over to the Usher Hall and the castle, were it not for the eyesores in our foreground: a concrete wall, crowd control barriers flapping with plastic hazard tape, and that weird grey igloo thing. Hard to know whether the latter is the council’s idea of an artwork, or a would-be futurist architect’s shed for street sweepers’ equipment. The other thing that’s wrong with our table is that it’s squashed in beside the service station. Seated, my dining partner’s head is about a foot away from our waitress’s elbow as she keys in orders. This table is snug in the wrong way. I guess it’s not a load of laughs to work here, perhaps that why our waitress clomps up and down gracelessly like the chatelaine of a boarding house, laying other tables loudly, possibly resentfully. In a film, she’d be played by Olivia Coleman.

There’s a produce map of Scotland on the menu. It talks virtuously of finest Scottish ingredients, local suppliers, seasonality, and so on. Judging from it my braised beef skirt should come from Berwickshire. Perhaps it does, but what fate befell it in these kitchens? It hangs off the fork in dry, grey strands, like an old string mop head the cleaner has left to dry. In place of the promised horseradish there’s sweet, gluey mayonnaise. This meat is propped up on frisée endive, half a slice of indifferent rye bread, the long-life, sliced commercial type, under stray circles of vinegary shallot. At least this starter is from the fixed price menu, so only £5, but the “shellfish with Thistly Cross cider and shallots” costs £10, and a meaner dish would be hard to find. It’s topped by a midget langoustine: all inedible head, and inconsequential, meat-challenged tail. There’s a small handful each of mussels that are barely big enough to consider as food, and unsubstantial clams. The most worrying element though is the queen scallops. Whatever their journey to our table, they’ve had a total flavour bypass. This dish doesn’t smell nice. The taste is creamy with a jarring dried herb presence, no apparent fish stock, let alone cider.

And now I’m staring in disbelief at this skate wing. £17, yet I have never seen a smaller one. It looks lost and lonely on its big white plate, dressed with a little butter and few broken up capers that have not been improved by deep-frying. Does the Sheraton instruct its seafood supplier to provide it with the smallest, meanest specimens on the slab?

READ MORE: Ron Mackenna restaurant review: Errol’s Hot Pizza, 379 Victoria Road, Glasgow

Pollock from the fixed price menu, although not singing out freshness, is adequately cooked. I could almost get enthusiastic about the yellow-fleshed salad potatoes it comes with until I taste the “Hollandaise” sauce that tops them: like floury Béchamel mixed with vinegar. These ribbons of cabbage are so long they could choke you. Their dressing adds a taint of stale garlic and poor oil, a palate polluter.

We gingerly sample a Tarte Tatin of French motorway service station standard, with clotted cream ice cream that evokes the greasy, sweet odour of an old tea towel that’s been lying around in a bakery for too long. A creamy rice pudding, stippled with vanilla seeds, needs more than this stingy teaspoon of rhubarb purée to stop it being cloying.

I’m just so grateful not to be paying for this meal with my own money. I wonder how many of Sheraton’s hotel guests feel the same.

One Square, 1 Festival Square, Edinburgh 0131 221 6422

Food: 4/10

Atmosphere: 4/10

Service: 4/10

Value for money: 4/10

Joanna Blythman

Guild of Food Writers Food Writer of the Year 2018