Turl Street Kitchen, 16-17 Turl Street Oxford

(Roger Askew )

At a scrubbed wooden table, a dapper, Rumpole-ish gentleman is taking lunch, in immaculate suit and wide red braces. Behind him, also eating alone, is a troll in human form – a small, wild-haired oldster wearing a plunging singlet and very short shorts, his abundantly furry chest and shoulders on proud display. Both of these unlikely fellow diners look perfectly at home.

Other lunchers today in this warm, woody set of Oxford rooms include a smattering of tourists, some chatty ladies-who-lunch (hello!) and several groups of students, or possibly models – since when did young people get so gorgeous? Any casting director seeking a mixed bag of quirky modern diners for a TV ad need look no further than the clientele of the Turl Street Kitchen, the gemütlich little restaurant putting the heart back into Oxford's city centre.

Let's be clear from the off – no one is going to make a special visit to TSK for the food. It's fine, in a home-cooked, kitchen-supper kind of way. Modern Brit fare, some of it trad – Barnsley chop, cottage pie, roast beef and Yorkshire pud on a Sunday – some of it from the dustier end of the Nigel Slater cookbook, such as garlic and bread soup, or trout gravlax with pickled cucumber. All lovely stuff, if not what you'd call destination dining. But Turl Street Kitchen has so much else going for it, that it doesn't really matter.

It's the kind of effortless neighbourhood café/bar/restaurant/whatever found in hip, studenty neighbourhoods the world over, but sadly rare in the UK. It's open from the early hours to the small hours, dispensing bacon rolls to May Ball-ers at dawn, and sometimes keeping the bar open for as long as people are spending. It hosts regular acoustic and open-mic nights, and showcases food sourced from within a 25-mile radius.

In short, it's hard to walk through the tessellated-tiled bar into the sunny, panelled dining room or sofa-filled snug without feeling lifestyle envy. The look, Georgian townhouse meets arty lecturer's kitchen, is hugely appealing. The tables are big, the menus small, changing twice daily to reflect their reliance on locally-sourced ingredients.

There were just six savoury dishes on offer when I went for lunch with my old university friend Cathy (we weren't at Oxford – she just happens to live there). Prices are student-friendly, ranging from leek and asparagus soup at £5, to rump steak with rocket and horseradish salad at £11.50.

The small plate revolution doesn't seem to have hit Oxford yet; each of our 'starter' salads could have fed four. Both featured good ingredients, chucked together in robust quantities. Big, silky hunks of beetroot walloped by salty slabs of Westcombe Cheddar and the mineral tang of watercress. Gloriously fresh soft-boiled eggs, nestling in a spa-break's worth of raw veg, including what seemed to be an entire little gem. "It's hearty provender," as Cathy said, possibly code for "I could have made this at home".

That the kitchen can also do cooking became clear from their smoked haddock fishcakes, fried to the ideal golden crunch, and perked up with split peas to add a bit of bite, and a blousy, vivid aioli. Lamb tagine was timidly spiced – more Tonbridge than Tangier – but rescued by some zippy, herb-packed couscous and yogurt-dressed leaves.

With a carafe of sauvignon blanc, and a huge picture window through which to admire the passing show, Cathy and I spent a very happy lunch. The staff are young, warm, and really confusing. One minute our handsome waiter was hunkering down, gazing into our eyes in soulful communion. Then he was off, ignoring us for long stretches, as if to keep us guessing. Rather like a boyfriend I had at college, as Cathy said.

Clearing our barely touched desserts, he shamingly murmured, "Was it a bridge too far? We did wonder, when you ordered so much food…" Actually, it was more that both puds were rather grim, particularly an oddity billed as 'chocolate crème brûlée', apparently an uncooked hot chocolate pudding in the process of regeneration. Still, it was struck from the bill as speedily as a girl's phone number from a faithless boy's address book at the end of summer term.

We paid a reasonable £65, including wine and service. And here's the best bit – TSK is a not-for-profit enterprise, raising money for the Oxford Hub charity, which promotes student volunteering and social action. So far it seems to be working – they've announced plans to turn a former bank nearby into a café and takeaway. With chains choking the city centre like bindweed and the old traders of the Covered Market being forced out by rent rises, it's great to see an ethical, independent-minded place like Turl Street Kitchen – and its independent-minded, variously costumed customers – taking centre stage.

Turl Street Kitchen, 16-17 Turl Street Oxford (01865 264171)

Around £20 a head for three courses

Food ***

Ambience *****

Service ****