The Classroom, CAVC City Centre Campus, Dumballs Road, Cardiff CF10 5FE (029 2025 0377). Meal for two, including drinks and service: £60

Even the greenest of cities have their tattered edges and Cardiff, which is greener than most, is no exception. If you get a window seat at this week’s restaurant, try not to look straight down. You’re more likely to catch sight of copulating seagulls on the battered roof of the industrial unit across the road than anything particularly inspiring. (Unless shagging seagulls does it for you; each to their own.) Fix your eyes instead on the verdant horizon, on the lush parks that run up to the hills surrounding the Welsh capital.

Better still look inwards to the airy space of The Classroom, the restaurant venture for catering students located on the fifth floor of the city centre campus of Cardiff and Vale College. It’s a lofty vault of sunlight and optimism, and reassuringly good food. I could claim it’s a useful addition to Cardiff’s burgeoning culinary scene but this would be a lie because, while the city has many good things to recommend it, the eating opportunities are not among them. So no, it’s not just a useful addition. It’s more than that.

Ah, listen to the howl of outrage. Cardiff is a greedy person’s nirvana, they insist. Or perhaps not. Given the city’s size and its population of 340,000 – more than a million in the wider metropolitan area – the choices are limited. On the upside it appears to have a number of interesting kebab places. Last year when Wales Online published its list of Cardiff’s 50 best restaurants, it included burger joints, a couple of chains and a cheese shop with a café that actually boasted on its website of the appalling service. Oh, and quite a number of interesting kebab places.

‘Soft and smooth but unashamedly rich’: chicken liver parfait. Photograph: Adrian Sherratt/The Observer

I should also point out that at 10.30pm on a Thursday night in the city centre, desperate for something to eat, I had to resort to a bacon double cheeseburger from Burger King, because literally nothing else was open. Some of you will doubtless tell me I wasn’t trying hard enough because there are quite a number of interesting kebab places. But the truth is I rather liked it. Remember, inside every restaurant critic picking at their plate of roast swan, is a filthy dirty food slut fighting to get out.

Still, it does mean that alongside bankers like the Potted Pig and Purple Poppadom – if it begins with a P in Cardiff it’s a winner – the Classroom really is worth knowing about. The idea of a restaurant in which students practise their trade for paying punters is nothing new. I should disclose that the day I ate there most of the students were elsewhere, graduating, and the Classroom was running a special menu for those celebrating the end of their degrees. That said, an apprentice was still working in the kitchen, alongside the hardened professionals who are always in attendance, led by head chef Alex Smith. (Chefs like James Sommerin and Hywel Jones are also involved with courses here).

Perfectly seasoned: Thai fishcake. Photograph: Adrian Sherratt/The Observer

That Graduation Menu, at £18.50 for three courses, reads like a cooking syllabus: a soup, a fishcake, a parfait (served with bread baked on site) or a savoury tart to start; a fish dish, a coq au vin, steak and chips, and a plate of gnocchi for mains; a chocolate tart; a posset and some ices to finish. Get across all those dishes and you’d have more than a hand hold on the fundamentals of what we’re now meant to call Modern European cooking.

That Graduation Menu reads like a cooking syllabus

They do these things well, some of them very well indeed. That fishcake is a perfectly seasoned ball of flaked salmon and cod, with scant evidence of potato filler, on a bed of wilted spinach with a deep pond of frothy, hand-whipped hollandaise. The scoop of chicken liver parfait is soft and smooth but unashamedly rich, as it should be for something made from the inner bits of the animal. It comes with their own thick-cut toasted brioche, made with enough butter to make the spreading of more redundant.

A fillet of cod, seared until the skin is crisp, falls apart with the nudge of a fork. It lies on a pillow of mash with a creamed fish sauce, which may not quite be the essence of the bouillabaisse the menu claims, but which is still a ripe old slap of seafood cooked down to become the very best of itself.

Well assembled: ‘coq au vin’. Photograph: Adrian Sherratt/The Observer

But it’s the take on coq au vin which seals it for me. On the menu they put the title in inverted commas and rightly so, because this is not a long-cooked stew but an assemblage. Happily, it’s been assembled bloody well. There’s a roasted chicken breast, skin crisped, the whole sliced on the bias. It lies on more mash, with a few greens off to the side for your good health. It’s surrounded by crisped lardons, button onions and mushrooms, as it should be. What brings it together is the sauce. It is the colour of a well-varnished oak table. It has the kind of stickiness that makes you smack your lips without forcing you to reach for a glass of water. It is deep and rich, without being cloying. It is a masterclass in careful reduction.

Which is when I ask the chap looking after us whether everything is made here. Yes, he says: the sauce, the hollandaise, the parfait, the bread. It’s mildly depressing that I’m impressed by this. Then again the dirty secret of professional catering is that the dark arts of the food service companies – sauce bases and chips, salad dressings, breads and cakes and the like – can slip unannounced on to the menus of even some of the fancier places. In truth the food service companies are just getting very good at this stuff, as proved by the pastry shell used in a chocolate and whisky tart which the kitchen freely volunteers is the one thing they’ve bought in. During graduation week trade can be brisk, and it’s a useful shortcut.

‘Dark, bitter, not too thick’: chocolate and whisky tart. Photograph: Adrian Sherratt/The Observer

We’ll allow them that. It’s a clever pastry shell: crisp round the edges, light and spongy beneath. The rest is theirs, including the chocolate and whisky filling which is dark and bitter but not overly thick, and the smooth vanilla ice cream. A lemon and passionfruit posset, under an almond crumble, could have been a little sharper for my taste – but it is only my taste. You get the idea. I like the Classroom. It’s not trying to innovate. It’s not pushing any boundaries. It’s just trying to teach the fundamentals. And it’s the diner who benefits.

Jay’s news bites

■ One of the more spendy student-run restaurant operations belongs to the Tante Marie Culinary Academy in Woking. Prices are a bit steep, with main courses in the high teens. But then the Tante Marie is a stand-alone high-end cookery school. Dishes on a recent lunchtime menu included guinea fowl ballotine and spinach mousseline (tantemarie restaurant.co.uk).

■ Thomasina Miers’s Mexican chain Wahaca is moving in off the high street to supermarkets. They have launched a range of taco kits into select branches of Tesco. The packs retail for £3.69 and include corn tortillas, marinades and salsas with differing levels of heat and spice (wahaca.co.uk).

■ Sports fans in Bristol have something to cheer. Josh Eggleton, chef of the Michelin-starred Pony and Trap in Chew Magna, has been signed up as a consultant chef to the Ashton Gate stadium, home to both Bristol City FC and the local rugby team. His dishes will be served on match days (theponyand trap.co.uk).

Jay Rayner’s new book, The Ten (Food) Commandments, is out now (£6, Penguin). To order a copy for £5.10, go to bookshop.theguardian.com

Email Jay at jay.rayner@observer.co.uk or follow him on Twitter @jayrayner1