The Old School, Gloucester Green, Oxford (01865 236 899). Meal for two: £50-80

Some dishes don’t so much speak to you as holler. They make a case for themselves just by sitting there being brown and crisp and hyper-spiced and brazen. So it is with the lamb ribs with cumin at My Sichuan in Oxford. This one dish is enough to have me battering away at the National Rail app, calculating journey and eating times, and wondering whether I could do the round trip by myself without anyone noticing my absence.

A plate of the lamb ribs, with some of their glossy, jade-green vegetables to make you feel better about yourself even as you scarf the animal fats, and the world would rest easy on its axis. Who needs dining companions when you have a plate of those? More to the point, why would you want a dining companion? They’d only insist you share. Nobody wants to share My Sichuan’s lamb ribs with cumin. OK. I don’t want to share. Go away. Mine.

As ever with Oxford, I find its restaurant sector baffling. All that money – the place heaves with international students on fat stipends; all that cosmopolitan good taste (cf note re rich international students); all that apparent interest in the world. And yet on the walk from the station we pass identikit chains, a splatter of pan-Asian restaurants which know how to make a catering-size pouch of pre-made Thai green curry paste go a bloody long way, and sanitised “urban brasseries” serving limp Caesar salads and festering rib-eyes, for the better-heeled students to be spoilt in by their parents.

Certainly on a Monday lunchtime, when I have to be there, the choices are very limited. (A new opening in Oxford that I have my eye on doesn’t even bother opening until Tuesday evening and gives up again at the end of Saturday; people of Oxford, I feel for you.)

To be fair, good non-Cantonese Chinese food has until relatively recently been a hard ask in Britain anywhere outside London and Manchester. A couple of stalwart chains have done a good job of bringing something deeper and funkier to deprived parts. Otherwise it’s a lot of glossy, oversweetened things and crispy ultra-deep-fried things.

Even My Sichuan, which clearly does a roaring trade in banquets for visiting Chinese groups – two are in the day we are there – has a menu of Cantonese standards. It is dispiriting that the only other non-Chinese punters in this lunchtime order crispy duck and the mixed starters of prawn gravel on sodden toast and leaky spring rolls. I want to lurch over to them, grab them by the lapels and bellow: “What are you doing? Why did you bother coming here if it was just to eat this stuff? That picture-led menu in your hands is the gateway to divine gustatory pleasures beyond your feeble imaginings.” But that would be hideously patronising and pretentious and I am meant to save such outbursts for this column.

So I stay at my dark-wood table beneath the handsome blue-glass cupola of the Old School building. It’s another bit of the honey-coloured stone that Oxford does so well, given a vaguely Chinese makeover by the addition of a few screens, dodgy art and some very big tables with lazy Susans in the middle.

It is a cold day so we start with a little shredded chicken and pickled vegetable soup to warm ourselves up. It is crystalline and bright and sharp and soothing: like Jewish penicillin that’s been given a rhinestone makeover without losing its very essence. The broth feels like it is taking care of you, which at £2.80 a bowl is something of a bargain.

And then the main event, starting with those tiny lamb ribs crusted with a mix of salt and chilli and cumin and just a dusting of sugar, the meat cooked so dark and served so hot that any layer of fat seems to burst beneath your teeth as you crunch down to find the soft meat beneath. As you work your way through the pile, you find on the plate a mess of finely chopped and fried garlic through which to dredge them. Even as I eat these ribs I know I will stink afterwards, but I discover I really don’t care. Are they truly Sichuan or do they have more in common with the barbecued meats of Xinjiang? It turns out I don’t care much about that either.

A special of their braised pork in soy brings cubes of bright-pink belly, long- and slow-cooked, with slippery fat the colour of well-worn ivory that breaks up on the tongue. It sits on leaves of Chinese cabbage, the whole in a broth with an indecent depth of flavour. A whole sea bass Chengdu style arrives looking like it must have been utterly overwhelmed by its overcoat of bean curd, chilli and garlic sauce. It fillets easily to reveal a pearly white flesh which can still hold its own and fight through to give a lightness to what otherwise looks heavy and cloying.

So far, so very animal protein. What’s striking is the equal clarity of the non-meat dishes. A huge heap of julienned potato has been fried only enough to stop it being raw and long before it has taken on any colour. Each strand has just a little bite and comes with red chillies for flavour and a fair dressing of sesame oil. I find it hard to think of another potato dish from any culinary tradition that deserves to be called fresh. Water spinach, a shoreline vegetable with tubular stems, dressed with garlic and chillies is equally invigorating.

And at this point I can see I’ve gone off on one. I am a lost soul. But the food here is so compelling and such good value I can’t help myself. Those lamb ribs are less than a tenner; even the whole sea bass is just £16.80. The short wine list is unremarkable, save that alongside crappy mass-produced South African chenin blancs and so forth, priced in the teens, they have bottles of Château Talbot at £160 a pop.

Service is solicitous in the matter of where we would should sit – as advised, it is indeed chilly by the bogs, so we move – but after that it’s functional rather than warm. We ask for the dessert list and even they look doubtful. Quite right. It is mostly bought-in ice creams, and who wants one of those? After all, it would only interfere with the memory of the lamb ribs.

Jay’s news bites

■ When I reviewed Sichuan Folk off London’s Brick Lane a year ago I worried that quality would depend on them retaining their chef; happily, reports remain positive. Start with a bowl of their addictive caramelised, sesame-sprinkled walnuts and their tiny sweet soy-dressed dumplings. Do not miss the whole crispy fish drenched in a boisterous sweet-chilli glaze (sichuan-folk.co.uk).

■ Excellent news: it’s almost Easter. At least Mars thinks so. It has just announced a range to mark the story of the resurrection. Products include the “MaltEaster” bunny in a cardboard campervan gift set. No, we have no idea what campervans have to do with Easter.

■ Dining website Hot Dinners has listed places open for Christmas Day lunch. So which are the most expensive? At number three it’s Galvin at Windows at the top of the Park Lane Hilton, at £250 a head. At two it’s Marcus Wareing at the Berkeley at £375. And at number one? It’s the Ritz hotel, where lunch – turkey or venison Wellington – will set you back £400 a head. Merry Christmas (hot-dinners.com).

Email Jay at jay.rayner@observer.co.uk. Follow Jay on Twitter @jayrayner1