This article is the subject of a legal complaint made on behalf of Otarian London Limited

Otarian, 181-183 Wardour Street, London W1. No booking. Meal for two, including wine and service, £25

Otarian did everything they could to ensure I hated them before I tasted a forkful of their food. It began with a press release in which they described themselves as "The planet's first low-carbon restaurant". Let me say this: I am completely supportive of any business that puts sustainability at the heart of what they do. To not think about these things would be reckless. What I hate is shameless grandstanding, an attempt to beat the opposition through false claims. It makes the thoughtfulness at the heart of a sustainability policy look hollow and bitchy.

So it is with Otarian. There are numerous restaurants which have put their impact on the environment – which means their carbon footprint – at the centre of their activities, most notably the lovely Acornhouse in London's King's Cross and the Field Kitchen at Riverford Farm in Devon. To claim, as Otarian does, that nobody else has ever considered this is either ignorant or deceitful. The most they can really claim is an interest in carbon counting.

The irritations continue on the premises, two of which have recently opened within a mile of each other in London's West End. They have taken the fast-food model; nothing wrong with that, it works for Leon and it could work here, too. The clean, crisp look of the place, all wipe-down tables and flashy plasma screens, is not offensive. But I could never tire of slapping whoever instructed the staff to utter the words: "Thank you for saving the world one Otarian meal at a time," as you finish your order. In the bumper book of utter marketing bollocks that has to be entry number one. Followed closely by the inclusion of the letter "O" for Otarian in dish names, on the entirely vegetarian, pictogram-sodden, multi-ethnic menu. So you are invited to try a "Penne O Gratin" pasta dish or a box of "spiced coconut curry O lime rice" or a "crème O brûlée". Stop it, people. Stopitstopitstopit.

The curious thing about this, the frustrating thing, is that the food isn't bad. It's not earth shattering, and I'm not even sure I would ever choose to eat there again. But almost everything we tried was well made and properly seasoned.

A bowl of gazpacho was big and punchy and bobbing with crisp cubes of fresh vegetables. Roasted vegetable couscous was packed full of green herbs and was light and brisk. That irritatingly named spiced coconut curry was unashamed in its spicing. Only a vegetable biryani failed to pass muster on account of dryness. It needed sauce. But even then the grains of well-spiced rice did not clump together. A panna cotta under a berry compote was equally well made. They've got the food right. What they've got wrong is the concept. It has been over-thought, over-sold and, unlike the food, completely over-cooked.

Email Jay at jay.rayner@observer.co.uk or visit theguardian.com/profile/jayrayner for all his reviews in one place