It was something of a game of moans. Last month a senior HBO executive described Belfast as "not the most cosmopolitan of cities" for the writers of Game of Thrones to be spending their downtime in. Belfast bristled. Michael Lombardo apologised. The "incredible partnership" (not to mention the generous tax arrangement) between the city and the hit series survived.

Lombardo may have put his foot in it but the truth is, he’s right. Belfast is not a cosmopolitan city. Neither is Dublin. But cities are like families. Outsiders don’t get to dis them.

Just a week before Lombardo played the villain of Belfast, a chef was crowned a tourism hero in Northern Ireland. The garlanded one was Niall McKenna, who owns three restaurants in the city and has plans to open a fourth in the Titanic Quarter.

McKenna opened James Street South in 2003 after a successful career at the stoves of some of London’s top restaurants. He brought a grown-up restaurant home to an elegant room on a side street where people could know that they were going to be well looked after.

Now in its second decade (do restaurants have a difficult second decade like a difficult second album?) McKenna has added a bar and grill upstairs and a cookery school. His third midrange restaurant, called Hadskis, has been added to the stable. So I’m interested to see how the mothership is faring with all this heroism and expansion. The first impression is of a refuge, especially on a hot day when you’ve walked for miles in shoes that started out comfortable and now feel like instruments of torture.

There’s a smell of butter and a relaxed friendly pair of wait staff who are taking plaudits from a diner in the corner to the kitchen. The room is a combination of pale grey and oak walls, gorgeous arch windows and a huge landscape painting set in panels on one wall. “Tell him it was absolutely superb,” the man says. “I will. He’ll be chuffed,” the waiter says smiling.

At least two other tables are having a long lunch. No one seems hassled or harried. A glass of the Moillard Mâcon Villages helps the shoulders to drop a couple more notches lower. I am chuffed too.

Nothing on the plates does anything to dent that. The starter plate is a set of small mouthfuls from a silky chunk of cured salmon through a crisped Jerusalem artichoke with roasted mushrooms that have gone from woodsy to toffee. There’s a butternut squash puree that has been buttered to the eyeballs and a langoustine in a frothy citrus Hollandaise with the greenest asparagus I’ve seen since I last ate it fresh out of my dad’s asparagus patch.

The only slight dip is a pork belly that is a touch dry. But it comes with that heroic ingredient, a slice of smokey Lough Neagh eel, which I’m hereby launching a one-woman mission to get onto all Irish menus.

A John Dory comes brilliantly cooked on hot cream-soaked lettuce and onions. Beside it like a chef’s xylophone, there are two spears of sweet white asparagus with bright green broadbeans dotted along their lengths and half radishes book-ending the picture. There are dots of honey on the plate. And razor clams add a salty rubbery grit to all the slick smoothness.

I picture my chocolate lime dessert as some kind of Heston-esque pretend lime with a chocolate mousse in the middle. But it’s much more evocative of childhood. There’s a wood-shaving curl of boiled sugar on top of a dark chocolate circle with some gold leaf to make it look all fancy. But in fact it’s a lime chocolate satin (you might remember them as chocolate pillows. My in-laws know them as chocolate satans) those boiled sweets whose sugary hit melted into chocolate the longer you sucked.

One great restaurant does not a cosmopolitan city make. But it's no coincidence that Belfast's groundbreaking Ox Restaurant is the work of Stephen Toman, a former head chef at James St South. There's a simple quiet competence in the kitchen here and a great use of ingredients from Northern Ireland's summer larder. A more cosmopolitan critic might say it's a restaurant that doesn't aim to wow with innovation or surprise. But that's fine by me. James Street South, 21 James Street South, Belfast BT2 7GA Tel: 0044-28 9043 4310 Facilities: Fine Music: Light pop Food provenance: Limited. Silverhill duck and Antrim beef are mentioned Wheelchair access: Yes Vegetarian options: Good THE VERDICT: 8/10 A lovely restaurant of which Belfast can be proud