Not least among the many glories of Oxford’s superbly renovated Ashmolean Museum is the splendid restaurant that has been created on its top floor. With wide picture windows on two sides, it commands stunning views over the city; there’s plenty to gawp at inside, too, if like me you consider an important part of the eating-out experience comes from observing the foibles of one’s fellow diners.

A young lady at a table two away from us last week kept us enthralled – and appalled – by a two-hour performance with her food. Having chopped the lot into a mash of even consistency, she then proceeded repeatedly to raise a forkful of it towards her lips only to withdraw it again at the last minute when she realised chewing might necessarily lead to an interruption in the non-stop flow of conversation she was directing at her long-suffering companion. I felt like giving her a round of applause when the by now icy morsel was at last masticated.

As it happens, I felt I too deserved congratulation for downing a dinner I didn’t really want. Forty-eight hours earlier I had returned from Turkey suffering from what a Cockney might refer to as a ‘dose of the toms’. Another night might have been better for a restaurant reviewing excursion, but a punishing schedule of pantomimes to criticise precluded this. It says much for the excellence of the food at the Ashmolean Dining Room that it managed to hit the spot in trying circumstances.

This is a proper restaurant in its own right rather than a mere nosebag for museum visitors. Helen Peacocke made this clear in her article a month or so ago in which were introduced ‘local lads’ Ben and Hugo Warner who run it (their company also caters at the V&A, the BFI and the natural History Museum, among other places).

Apart from anything else, it’s open when the museum is closed – every evening except Sunday and Monday. You go in through the side door from St Giles’s where a welcoming young lady waits to take your coat and show you into the lift. Pushing aside the door into the restaurant, we expected to find few others there on this Tuesday night. In fact, it was nearly full – and there were quite a few people we knew.

Having settled at our table, we were supplied, mysteriously, with a plate of large fresh radishes, toasted ciabatta and black olive tapenade (‘mysteriously’ because it said it cost £3.50 on the menu and this was complimentary).

Divining, correctly, that a bowl of soup would tempt a jaded appetite, I ordered the ribollita. This Tuscan favourite – a version of minestrone – proved good to eat even if some of the ingredients, the potatoes and white beans especially, were a tad crunchy and could have done with longer in the pot. It would have been better the next day after the ‘reboiling’ that is the meaning of its name.

By contrast, the square of boulangère potatoes that came with my main course of chargrilled sea bass had evidently been hanging around too long in the heat, possibly since lunchtime, and was rather dried out. Not so the fish, though, which was beautifully cooked, the moist white flesh ready to burst through the seared skin. It came with fresh-tasting gremolata and super buttered chard.

Rosemarie, meanwhile, had eaten two starters and thoroughly enjoyed them, but for the slight reservation over the second – poached eggs, braised shallots, pancetta and Burgundy sauce – that she would have preferred the eggs runny. First up had been a generous portion of pork rillettes with cornichons – one of a number of charcuterie choices available, including classic French saucisson and smoked venison.

You can check out the menu on line. Other highlights for me (to be tried in the future) include pot-roast partridge, Cornish fish stew and two onion tart.

Dinner was completed for me with a portion of Two Hoots cheese (an award-winning blue from Barkham, in Berkshire) with pears and marinated muscat grapes – but no biscuits, which I thought a curious omission. Rosemarie had a smashing treacle sponge with Jersey clotted cream. Service throughout had been friendly and efficient.

I was back at the restaurant as someone’s guest for lunch two days later. The place was packed to the seams and looked its best with sunshine streaming in (roll on summer when we can be out on the terrace). Three cheers this time for the chargrilled marinated squid, salted cod croquetttes with saffron aïoli, quails’ eggs, and roast suckling pig with salsa verde and Castelluccio lentils.

This is a very welcome arrival on the Oxford restaurant scene, and I expect to be making many more happy visits in 2010.

I shall be missing next week, so I wish you all a very happy Christmas.