Bébé Bob is ridiculous in all kinds of ways. Let me start with the decor: the plush, cherry-red carpets, the velvet chairs, the marble tabletops, the mahogany panelling and the beige leather banquettes. Basically, it gives off “chicest dining option on a swanky 1960s cruise ship, complete with a swarm of seagulls chasing you from Civitavecchia to Cartagena” vibes; it also zings with “restaurant adjacent to a Monte Carlo poker table where James Bond might woo Honey Ryder”, although 007 would have to bet on Honey loving chicken, because that’s the only main course Bébé Bob offers. One bird, served for two, with legs, thighs, wings and breasts on a plate with a kitsch red logo.

Bébé Bob is essentially a rotisserie restaurant wearing a fur coat and Rigby & Peller knickers. Selling just the one item and doing it well is very much du jour in restaurant-land these days, though: it cuts costs, faff and fuss, while at the same time emitting an air of culinary expertise. Bébé Bob, as you may have guessed from the name, is a pared-down spin-off from the nearby well-established Bob Bob Ricard, which is best known for its Instagram-friendly “press for champagne” buttons, chicken kiev and -18C shots of Staritsky Levitsky small-batch vodka. Bob Bob Ricard is completely ridiculous, so it is a huge relief that its little sister doesn’t let it down.

Now, about those birds on which the menu so heavily relies: Bébé Bob serves either Vendée chicken from Pays de la Loire or Landaise chicken from Gascony, both the kind of plump, painstakingly reared bird that weary food experts advise us all to eat, rather than £6 supermarket chooks with gammy legs and cysts. Vendée chickens have no such woes – these are VIP chickens, VICs, if you will. Landaise chickens are such exclusive cluckers, meanwhile, that they didn’t even show up on the day we visited. “We only have Vendée today,” our waiter said, without even acknowledging that this meant the tiny menu had at a stroke been effectively halved. I couldn’t be cross about it, though. The place is too tongue-in-cheek silly to get mad at. “Inspired by the golden age”, this boss-level KFC says on its glitzy website. “Fashionwear is welcome, activewear is not … Guests under 15 years old are not admitted,” and the really quite brilliant: “Tables are available for up to four guests only. Larger groups, alas, cannot be accommodated.”

The fabulous, pass-agg positioning of that “alas” makes me purr with joy. Offity-fuck you go, Kardashian clan, with your extended broods and your Balenciaga-Adidas spandex workout stilettos. No posh chicken for you! No truffled fries. No delicious sides of chicken fat-encrusted roast potatoes, honeyed parsnips and carrots, also drenched in chicken fat. All of them are outstanding, by the way, this being VIC fat. Charles griped that his own roast chicken is better, softer and seasoned more deftly, but I argued that he makes just the one at a time, not 100 of the things, so we could maybe cut them some slack. We’re still arguing about that.

Bébé Bob may well be accused of having a lot of swagger for what is essentially a roast dinner restaurant round the back of Regent Street, yet, via smoke and mirrors, the whole thing hangs together rather well. The menu’s list of starters could easily be a paean to Margo from The Good Life entertaining Mrs Dooms-Patterson. There is prawn cocktail with VSOP cognac-infused marie rose sauce, eggs mayonnaise draped with Cantabrian anchovies, a dressed winter leaf salad and smoked salmon with buttered rye bread. None of these will bend the mind of a dedicated gourmand; they are just tasty, inoffensive versions of Franglais dining classics. There is caviar, too, if that’s your bag: Siberian, Oscietra or Amurski, with creme fraiche and blinis, plus, if you can’t choose, a £49 dégustation plate featuring all three.

We ate one Saturday lunchtime in a sedate but still jolly room of families, couples and groups of friends who clearly didn’t mind keeping the guest limit to four. Who needs more than three friends at dinner, anyway? Any more than that, and it’s just noise, and all those dishes you foolishly agreed to share end up at the wrong end of the table. Perhaps Bébé Bob has a point: four is just the right amount.

With the choices for starters and mains so brief, desserts are similarly lightly administered. Unless you’re in Fuerteventura, a shot of lemon-infused vodka is not, strictly speaking, pudding. Neither is a scoop of lemon sorbet doused in vodka, although the booze might numb the pain of it costing £9. Being a creature of habit, I went for the Paris-Brest, because there is no such thing as a bad one. Show me a collision of choux pastry, praline cream and blanched almonds that I’ll balk at? Impossible. It wasn’t the greatest Paris-Brest in London (that would be Cédric Grolet’s Paris-Brest flower over at the Berkeley, a snip at £35), but it was definitely decent. Bébé Bob is a chicken-and-chips joint that thinks it is “it”, and I shan’t tell them otherwise.

• Bébé Bob 37 Golden Square, London W1, 020-7242 1000. Open Weds-Sun, lunch noon-3.30pm, dinner 5.30-11.30pm; Sat noon-11.30pm; Sun noon-10.30pm. From about £40 a head; express lunch (chicken, chips and salad) £24, all plus drinks and service