Fitzbillies, 51-52 Trumpington Street, Cambridge

Fitzbillies' art nouveau windows display the kind of many-tiered wedding cake that Downton's Mrs Patmore might have sweated over for days (TIM HAYWARD)

I'm walking through Cambridge at twilight, and there's a touch of magic in the misty air. Lights twinkle distantly behind college windows. Students stream past on bicycles, heading back to their digs. Apart from the fact that most of them are talking on mobile phones, we might have slipped back into another century.

My destination, the Cambridge institution Fitzbillies, maintains the time-slip illusion. Its art nouveau windows, apparently unchanged since it opened in 1922, display the kind of many-tiered wedding cake that Downton's Mrs Patmore might have sweated over for days. The shop-front is in semi-darkness. Then, from the shadows, a burly man in chef's whites steps forward to the window, and begins to light the silver candelabra with a sacramental intensity.

I recognise him as Tim Hayward, though the last time I saw him was in a different context; as a fellow judge at a rather rowdy restaurant awards lunch in London. Could this calm, priest-like figure, surrounded by camply decorated baked goods, really be the tattooed hard man of British food writing? Could the editor of the magazine Fire and Knives really have regenerated amid candlelight and teaspoons?

In a bold move, last year Hayward and his wife left their London home, and in Alison's case, a high-flying marketing career, to buy Fitzbillies. This much-loved purveyor of fine cakes and slightly touristy lunches had gone into receivership, to the dismay of locals. Undeterred by their relative lack of hands-on experience – Tim had cooked in American diners in his youth – the Haywards stepped in.

What they did have were contacts, and soon they'd assembled a formidable A-Team, led by the inspirational chef Rosie Sykes, ex of the Sutton Arms in Smithfield. Former employees returned, including the head baker and the 83-year-old icing maestro responsible for those Downton-worthy display cakes. An expanded Fitzbillies reopened for business last summer, as cake shop, coffee house and restaurant, with Tim himself taking on the role of occasional chef, and on the night of our visit, maître d'.

With a kitchen-ward cry of "Boss, we're on!", he welcomed us, and for the rest of the evening, bustled around looking like a very happy man. The dining room, currently open for lunch and weekend dinner only, is plain but welcoming, a neutral space lined with tongue-and-groove and perked up with some framed foodie-bilia.

That simple, unadorned good taste extends to the shortish menu, which could be subtitled 'things you really want to eat'. Seasonality and regionality are assumed rather than trumpeted, and there's a distinctly British feel to many of the dishes, even if steak and ale pie comes with Vichy carrots, and poached chicken with lentils and green sauce (not salsa verde, you note).

Some of the Anglicisation is a little clunky. My starter was the odd-sounding 'Burgundian poached duck egg', but then again, if they'd called it oeuf de canard pochée à la bourguignonne, I wouldn't have ordered it. I was glad I did. Like a poached egg on toast that had elbowed its way into a boeuf bourguignon, it was an unusual but deeply satisfying dish.

My guest Ireena's salad of shredded fennel, red cabbage and chervil also came with a twist, in the form of a galvanisingly bold anchovy dressing. Special mention, too, for the bread: we were offered two sorts, a springy, golden-crusted white made with buttermilk, and a cake-like soda bread so good I blagged a spare loaf to take home.

The bread oven is at the heart of the kitchen, and several of the main courses are slow-cooked in its residual heat. Shoulder of kid had been pot-roasted in wine, and came with 'baker's oven potatoes', cooked, Lyonnaise-style, in a sweet mulch of shallots.

At the other end of the ascetic spectrum from my Desperate Dan-scaled hunk of meat was Ireena's spiced rice and chickpea pilaff. So perfectly did it recall her mother's homemade kitcheree, it reduced her to a state of Proustian confusion, though a raita-like fresh cheese scented with coriander and chicory and red onion relish took the plateful to another level.

The fine balance of delicacy and generosity continued with our puddings, rhubarb tart with a Seville orange and caramel ice-cream, and spiced chocolate cake studded with caramelised almonds, like a cakely incarnation of panforte.

The generosity of the portions and relatively low prices reflect the Haywards' desire to reinstate Fitzbillies at the heart of the community. The young staff match the tongue-and-groove walls, being both distinctly groovy and endearingly chatty; one waiter chipped in from across the room to give his opinion of a comedian we were discussing. Stuffier diners might find that intrusive; but this being Cambridge, let's call it collegiate.

To find a restaurant as good as Fitzbillies anywhere would be heartening. To find one in Cambridge, notoriously the UK's worst 'clone town', is inspirational. If this is what a foodie's mid-life crisis looks like, just hope that there's one coming to your town soon.

Fitzbillies, 51-52 Trumpington Street, Cambridge (01223 352500)

Around £30 a head for three courses, before wine and service

Food ****
Ambience ****
Service ****

Tipping policy: "There is a discretionary 12.5 per cent service charge on groups of six or over; no service charge otherwise. All tips go to the staff"

Side orders: Classy Cambridge

Cotto

Rack of salt marsh lamb with thyme and parsley herb crust, salad and sautéed potatoes costs £23 here – the focus is on locally-sourced produce.

183 East Rd (01223 302010)

The Punter

Stunningly renovated former coaching house serving impressive cuisine – try the slow-roasted Old Spot pork belly with black beans, celery and apple (£14.50).

3 Pound Hill (01223 363 322)

The Backstreet Bistro

Fillet of turbot pan-fried with baby onions, mushrooms, pancetta and red wine reduction will set you back a reasonable £15.95 at this popular local restaurant.

2 Sturton St (01223 306 306)