This eccentric Italian restaurant is buried in the basement of a Vauxhall office block. Formerly the premises of the famous Royal Doulton pottery – which specialised in decorative stoneware and salt-glazed sewer pipes - the building has been renamed Southbank House. Follow the lively chatter and whiff of garlic down a staircase lined with posters of the Amalfi coast to a boisterous dining room decked in gingham. Sirena’s opened in 1991, but the cheesy décor and menu are more 1971: prawn cocktail, melanzane parmigiana, pollo alla Milanese all feature. There’s a takeaway sandwich counter for the office slaves who eat at their desks but you’d be crazy not to stay for the cheap pizza, heart-stopping pasta, and wisecracking waiters wielding phallic pepper grinders. If only every office had a staff canteen like this.  Southbank House, Black Prince Road, Vauxhall SE1 7SJ; 0207 587 0683  Paul Rothe & Sons, Marylebone  This quaint café, which doubles as a delicatessen, has been in the Rothe family for four generations. A throwback to Marylebone before gentrification, Paul Rothe & Sons has preserved the old-fashioned charm of the village grocer, with its Formica booths and folding leatherette seats. Wood-clad walls are lined with traditional treats evocative of school fetes and family picnics - lemon curd, English mustard, peppermint humbugs and Highland fudge. The menu is also a smorgasbord of comfort food for the terminally nostalgic; there are marmite and cucumber sandwiches, salt beef, mustard and dill pickle baps, a mug of Bovril, a caramel slice. A few exotic items do feature, notably the Austrian liptauer (cream cheese with paprika, chives and capers) and kummelkase (stilton, caraway seeds and cream cheese) sandwiches.  35 Marylebone Lane, Marylebone W1U 2NN, 0207 935 6783  This Vietnamese food cart in a subterranean courtyard beside Chelsea Farmer’s Market is more appealing than its name suggests. (Phat Phuc means ‘Happy Buddha’ in Vietnamese.) Long before London’s recent obsession with street food exploded, this outdoor canteen was serving up steaming bowls of noodles to fragrant blondes. The short menu focuses on pho – a soothing broth of vegetables and vermicelli flavoured with chicken, beef or tofu. Traditionally a breakfast staple, pho is a very effective hangover cure (much better than a full English, and with none of the after-effects). Equally delicious are bánh cuòn (summer rolls with prawns or tofu) and bánh xeo (steamed pancakes with crispy duck and hoisin sauce). If all those giant vats of noodles start taking their toll on your waistline, you can invest in a Phat Phuc t-shirt.  151 Sydney Street, Chelsea SW3 6NT; 0207 351 3843  Platform is not your typical cafeteria, but the residents of Netil House are not your typical office workers. Pilates instructors, tattoo artists, illustrators and acrobats inhabit Netil House - a drab 1960s office block that was a community college, council offices and a squat before it became a hive of artsy activity. Accessed via a secret doorway down a grubby alley, the vast second-floor café has a wall of windows overlooking the East London skyline: there’s Canary Wharf to the left, the Gherkin and the Shard to your right. Trains chugging along the railway tracks at eye level give the scene a faintly futuristic edge. The menu is affordable, imaginative and changes daily; lentil, date and roast pepper salad or roasted vegetable sandwich with saffron-infused paneer are typically healthy fare. After dark, the café morphs into a bar, where Hackney’s hipsters gather for impromptu sing-a-longs, film nights and ping pong tournaments.  Studio 207, 2nd Floor, Netil House, 1-7 Westgate Street, London Fields, E8 3RL; 0203 095 9713  Written by Rachel Howard, Secret London, Unusual Bars & Restaurants bills itself as an antidote to food fads and celebrity chefs. Showcasing a collection of unusual places in unlikely locations, it celebrates independent businesses kept afloat by eccentric owners, and local institutions oblivious to passing trends, as well as the cosmopolitan spirit of London and the diversity found there. It is available through Editions Jonglez.
A number of low-key and hidden London restaurants are luring in-the-know   diners away from food fads, celebrity chefs and the tourist trail. Rachel   Howards selects five of her favourites.