5 Dean’s Court, London EC4 (020 7332 0858). Meal for two £20

A weekday lunchtime and I’m alone at the counter in the window of a new “healthy fast-food” concept. Oh sure, there’s always a queue of volunteers to join me for the hip dirty Italian in Hackney, or the hyper-delicious Japanese in Bayswater. But when new formats that could be coming to a high street near you very soon need checking out, not so much. Mind you, I’m grateful. I survey the quarter-eaten cardboard pots of stuff on a tray in front of me, which constitutes most of the hot menu at Suchef, and give thanks nobody wanted to join me. I’d have spent most of the meal apologising for wasting their time.

This, the first branch of Suchef, is tucked down an alley opposite St Paul’s Cathedral and looks much like any of the other glossy fast-food concessions surrounding it. There are wipe-clean surfaces, and lots of natural stone. It looks like the café in a high-class spa. A little whale song and they’d have sealed the deal. Which, given its claims for nutritional virtue, is probably the intention. The name is apparently inspired by two things. First, there is a nod to the sous chef – or second in command – in professional kitchens. Or as they put it: “Why is it always the chef that gets all the credit for the food and never the hard-working, ball-busting sous chef?” Well, probably because the sous chef didn’t come up with the dishes, deal with the budgets, hire the staff and take all the crap from the owners and the criticism from the punters when the sous chef screwed up. But still, it’s nice that they’re thinking of the troops.

The second inspiration is more curious: it’s the cooking method. The majority of the food here is apparently cooked “sous vide” or literally “under vacuum”. This means it’s vacuum-packed in plastic bags and then heated in temperature-controlled water baths. Various starry modernist chefs have been cheerleaders for it because it means they can pack away cuts of meat and fish with various aromatics, and cook them very precisely at lower temperatures without losing any flavour or juices to the pan.

The Suchef blurb references its use by Michelin-starred chefs and then says: “We don’t think it should be that exclusive.”

God. Where to start? First, there’s lots not to like about sous vide. Yes, it cooks animal proteins after a fashion. But it leaves them with a raw, mushy and frankly unpleasant texture. Kitchens try to get round this by dumping the cut in a pan of frothing butter at the end to bring on the all-important Maillard reaction – the caramelisation of sugars – that gives flavour. They end up with a cut of meat or fish that has rawness with one cooked side. If you don’t do this – if all you do is put the protein in a bag with no flavourings – you end up with something approximating baby food.

But there’s something else. Top-end restaurants may be using it, but it’s not exclusive in any way. It has been used in mass catering for years as a way of prepping food and then holding it until needed. There are doubtless a number of Suchef’s competitors on the high street that use sous vide in one way or another; they’re just not claiming it as a marketing point.

As to the health benefits, well, yes – cooking vegetables like this does mean you don’t leach nutrients out into the water. Though, as customers aren’t usually at risk of rickets or scurvy, the impact is going to be marginal. Apparently they are getting their nutritional expertise from a graduate and former tutor of the Institute for Optimum Nutrition. Those wanting a laugh should read the chapter on its founder, Patrick Holford, and the school itself in Ben Goldacre’s book Bad Science.

As it happens, there’s no legal definition of a nutritionist. You do need to be legally qualified to call yourself a dietician, but anyone can call themself a nutritionist. And so, for the purposes of this review, today I am a nutritionist. Speaking as a nutritionist, I would say most of the food at Suchef is pants. A price of £4.50 brings a pot of skinless chicken breast, cooked sous vide. It’s dusted with something orange and tasteless – perhaps paprika – and dots of chopped herbs. Otherwise it is unseasoned, flavourless and has the texture of cotton wool.

Worse is the salmon and plaice roulade, the latter wrapped about the former. It’s so soft you could eat it with a spoon or, if you had reasonable suction, a wide-bore straw.

You are meant to put these together with one of their sauces, costing £1.50 per tiny pot. The hot and spicy tomato is only mildly spiced and has the acidic tang of uncooked tomatoes. The SuSpecial oriental is spicier than the spicy tomato, and has a weird metallic back taste I cannot identify. Best of the lot is the mango and chilli salsa, which benefits from no cooking. There is freshness and bite. I pour the cream, mushroom and tarragon sauce over the fish roulade. Suddenly I have created one of those speciality meals for elderly people with chewing and swallowing problems on geriatric wards. This is not a good thing. Unless you are an elderly person with chewing and swallowing problems.

A whacking £7.95 gets you one of their hot-pot dishes. Today it’s a chicken green curry. I am minded to use the word “allegedly”, for it is a poor effort. The brilliant, zippy, spine-tingling green curry at KaoSarn in Brixton costs 5p less and gets you table service. This is dull, insipid and more than half rice. The ratatouille is a testament to the sous-vide technique; the vegetables taste undercooked and there is again that raw tomato tang. Unseasoned, undressed broccoli, sugar snaps and peas in a pot are simply sad. They look like leftovers from an uninspired dinner party.

And that’s the point. You can make all the claims you like for your cooking method and its nutritional value. But if the food isn’t very nice, why bother? What’s more, the notion of healthy fast food isn’t new at all. Leon has been doing it for years, and very successfully. Oh, their Moroccan meatballs! Then there’s the salad-based chains Tossed and Chop’d. They serve nice food, too. Suchef is planning a roll-out. Apparently they already have two other London sites picked out. All I can say is: good luck with that.

Jay’s news bites

■ A market-leader for healthy fast food has to be Itsu, which has nearly 50 eat-in “shops” in London and beyond. The combination of low-carb Asiatic salads, passable sashimi and quick miso noodle soups and dumpling pots distinguishes them on the high street. Yes, there may be some silly “detox” marketing babble. But the fact remains: this is fast food at a good price in a pleasant setting that doesn’t make you hate yourself (itsu.com).

■ Malton in Yorkshire is trying to secure its position as the county’s food hub by offering units for small food businesses that want to step up from being “kitchen-table” enterprises. The six low-priced units at Talbot Yard come with A1 (retail) and B1 (light industrial) consent. (maltonestate.co.uk)

■ Shocking news, if only to those with self-restraint: according to a survey by The Grocer magazine, almost a quarter of us buy sharing bags of confectionery – Revels, Maltesers, etc – and eat them alone in one sitting. That’s the equivalent of five standard bars of chocolate. Disgraceful behaviour. Awful. No, you can’t have one. They’re all mine. Now leave me alone.