Catherine Tate's Nan gave half an hour over to the comedian's bilious, racist, cantankerous and foul-mouthed septuagenarian, which was at least 20 minutes too much. Nan is basically one joke, and a good one at that, but her natural habitat is the sketch show, not the sitcom.

It's fair to say that Catherine Tate has had an interesting couple of years; from her role in the American version of The Office to acting on the stage, I feel she's come a long way since her sketch show. However this week saw her revive one of her most popular sketch show characters, Joannie Taylor, for a one-off special Nan.

At first I thought Nan would be simply an extended version of the sketch show, but the plot of the programme was fairly endearing. It saw Nan being paired with teenage volunteer Alice (Ami Metcalf) while her grandson (Mathew Horne) is off building a school in Africa. The main thrust of the episode concerns Nan's taps and her constant fights with the council to get it fixed. In her own unique style Nan's interactions with council representative Miss Donnelly (Nikki Wardley) land her in hot water and eventually see her serve two community service orders. Eventually though Nan is able to save the day by allowing her Indian neighbours to host a wedding in her flat.

Anybody who loved Nan's foul language and bad attitude wouldn't have been disappointed by what they saw here. However I was surprised that Tate fleshed out the character especially in constructing a relationship between Nan and Alice. I feel the episode really benefited from the appearance of Ami Metcalf, who so good as the young Kathy Burke in Walking and Talking. Metcalf and Tate made a fine double act and I particularly enjoyed Alice's confrontation with Miss Donnelly. The focus on the bureaucracy at the council was also a story that most people could identify with and they could understand Nan's frustration and the way she dealt with the problem was completely believable.

Ultimately I found Nan to be funny, endearing and a sitcom that was well-paced throughout. If all the episodes are of the same quality as this special then I wouldn't mind seeing Nan return for a full series at some point. But for now I can definitely say that Nan was a big surprise as I didn't see myself enjoying it at all.

Catherine Tate's Nan (BBC One, Saturday), back from the dead for a one-off appearance, a decade or so on from when she first appeared on Tate's sketch show. There is something of 10 years ago about it. The idea - foul-mouthed, mean, selfish, racist old dragon, moaning about the modern world and everything else - wasn't the most original idea even then. It doesn't really surprise: a lot of the gags announce themselves before they happen. Studio laughter is unacceptable these days. There might be a bit of swearing but no boundaries are being pushed.

But it is still fun - and funny - because of Tate's fabulous, full-on performance. All of her - eyes, shoulders, posture, hands, fingers (especially fingers), timing of course - is thrown into it, into being Nan. And I love that little machine gun cackle, ahahahaha.

Catherine Tate's Nan: More please!

In a recent article I bemoaned returning comedies, but without wishing to step all over my well made points I think Catherine Tate has managed to do it successfully.

Storm over foul-mouthed BBC comedy Catherine Tate's Nan

The BBC faces a fresh storm over Catherine Tate's foul-mouthed and racist comedy character, Nan.

Catherine Tate's Nan entertains on BBC1

Nan is a broad comedy pitched for the huge Mrs Brown's Boys audience; it could have had more bite given Nan's outdated attitudes and beliefs, but the BBC made sure Nan's dentures were removed.

Nan review

I loved Nan, it being the perfect follow-up to The Catherine Tate Show. Could it sustain a series? I'm not sure.

Catherine Tate's Nan review

Most of this year's Christmas comedy specials have felt like barrel-scraping, but Nan could easily hold her own in a full series.