61-63 Beak Street, London W1. No bookings. Meal for two: £20-£40

Let's rehearse the old gag: how do you make a small fortune in the restaurant business? Start with a big one. Oh, the oceans of cash that have been lost on the fragile dream of monetising the business of showing people a good time. On paper it looks straightforward. Flog nice food and wine to enough people, with a good enough margin and a smile, and happiness is yours.

The obvious problem is that the number of people willing to be shown a good time is never guaranteed, while the costs are. Rents and rates, utility bills and wages all have to be paid regardless of whether anybody wants to eat your finely honed dish of liver in lager. You can shed the odd waiter. You can trim your ingredients costs by compromising on quality – ignore the stirrups accidentally left in with the consignment of extra cheap "beef" – but it won't make a vast amount of difference. If you can't drag in punters you'll quickly be wallowing in red ink. The gap between huge losses and cheery profits can be remarkably narrow.

And there's another problem with trying to make big money from restaurants. They work best when they are the expression of an individual. As a result it's hard to create a saleable asset. In its pomp, for example, Gordon Ramsay Restaurants was hugely successful. Its profits would have valued the whole business at north of £50m. Except that, if sold, it would become Gordon Ramsay Restaurants without Gordon Ramsay. That would be just so many lease assignments, wine stores and fine bone china, and no fruity expletives.

The more orthodox way to make money from people eating out is to create a replicable chain; a brand that can spread along Britain's high streets like chicken pox through a nursery. Ramsay understood this. It's why he bought the venerable Foxtrot Oscar in Chelsea – a hilarious play on his expletive of choice via the Nato phonetic alphabet – which was meant to be the cornerstone for a huge roll out, but never was.

Others have got it right. In October the 34-strong Byron chain of hamburger restaurants – George Osborne's favourite – sold for £100m. It was an enthusiastic valuation for a company earning £6.9m a year. But then the buyers weren't just taking over a bunch of restaurants. They were buying the potential to open a whole load more. A month before the Byron deal, Richard Caring (the chap with the blindingly snow-white teeth and the winter-in-Tunisia tan who owns the high-end Caprice group, including the Ivy, J Sheekey and Scott's) did a mass-market deal of his own. Côte, the chain of French bistros, was also sold for £100m. Caring owned 51%.

Now with Grillshack, opened just as Côte was being sold, Caring is at it again. Grillshack is worth knowing about because, if all goes according to (his) plan, there will be one near you shortly. Even allowing for concerns about the identikit British high street I suspect this one will be regarded as a moderately good thing.

The room is cafeteria chic, all hard wipe-down surfaces, cheery gashes of colour and US diner iconography. There are mustard-coloured walls and curving wooden slatted benches which echo the wooden venetian blinds. The all-day menu, designed by former Ramsay head chef Mark Askew, is short: a flattened rump steak with shoestring potatoes for £9.95, half a grilled chicken for £7.95, a haloumi salad for £7.75 and a couple of hamburgers, plus various sides.

What keeps the prices down is the utilisation of new tech. Although you can order at the counter, you can also do so from terminals in the room or, without getting up, via a smartphone app. The food is then brought to you.

I decide to be terribly modern and download the app, which I am told will work quicker if I access it via their own Wi-Fi. I have to input a lot of card details. Just before I send the order I notice that I don't need a side of shoestring fries because they already come with my steak. Going back to change the order is fine – except all my card details are lost and I have to start again. When it comes to ordering dessert I cannot be fagged with the effort. I give up and go to the counter. The app is probably most useful if you are ordering food to take away. It should also be noted that the process dumps at least three emails into your inbox, one of which looks like spam.

So far so tech. None of this is relevant if the food doesn't do the job. For the most part it does. In an age when getting a good steak generally involves selling your children on the open market to pay for it, the flattened rump here is very good value. We're talking a big sheet of very fast-grilled beef. Don't go looking for a pink tinge inside. It's so thin there is no inside. But it's tender, tastes properly of animal and comes with a rustling pile of matchstick-thin chips and a hunk of smoked butter. No Dijon mustard, sadly, which is an oversight.

The grilled chicken has crisp, well-seasoned skin and meat that hasn't been cooked to death. We like the seasoned fries. There are also a couple of specials on offer, including the obligatory pulled-pork bun. Breakfast options (until 11am) include pancakes, French toast and a bacon brioche all for around £3.50. This is a volume business run on very tight margins.

Not everything is thrilling. Buttermilk fried-chicken nuggets are hard and dry as if they've been hanging around a little while. A spin bowler could do damage with one of these. A crisp radish slaw is OK, if a little under-dressed. Corn on the cob with chipotle butter and grated hard (unnamed) cheese is probably fabulous the moment it's cooked, but less so a while later.

Dessert choices are narrow: a cheesecake, a passable carrot and walnut cake and the blunt instrument which is the triple choc chip cookie ice-cream sandwich. Drunk, late at night, one of those would make an awful lot of sense. In the cold light of day, the chiller treatment does the cookie no favours. And yet for all these (minor) faults, Grillshack is a robust proposition. I suspect that very soon there really will be one near you. And that, a little while after that, Richard Caring will make another fat dollop of money.

Jay's news bites

■ For another smart way to use technology try London's Honest Burger, which has expanded swiftly from one branch in Brixton to Soho, Camden and Portobello Road. They text you when your table is ready so there's no standing in line, just a casual saunter off for a nearby drink. The burgers are up there with the best; the rosemary-and-salt-dusted chips are quite simply addictive. Around £12.50 a head including drink and service (honestburgers.co.uk)

■ For those who spend a little too much time thinking about their dinner, Queen Margaret University in Edinburgh has launched a masters degree in gastronomy. It will study the world of food "from Michelin-starred restaurants to soup kitchens, community allotments to large scale agri-business". More info at qmu.ac.uk

■ Papa John's has gone all seasonal. Say hello to the Christmas pizza: turkey, sage and onion meatballs, pork sausage, bacon and a topping of "cranberry drizzle". Just how many types of wrong can you get on one disc of dough?

Email Jay at jay.rayner@observer.co.uk. Follow Jay on Twitter @jayrayner1