People scoffed in 2004, when Matt Dawson made his media ambitions plain by skipping an England rugby union get-together to honour a commitment to A Question of Sport. Four years on, though, with a Celebrity MasterChef title in the bag and with a creditable silver-medal finish in the fourth series of Strictly Come Dancing behind him, the only person scoffing is Dawson. And what he is scoffing is freshly caught and simply prepared seafood on Mitch and Matt's Big Fish.

The plan is for the former scrum half to tour Britain in a battered camper van, yank a few fish out of the water and prepare the catch for our delectation - all in the company of Mitch Tonks, a television chef specialising in seafood, who must regret living in the era of Rick Stein almost as much as Dawson must regret having danced in the age of Mark Ramprakash. In the course of the first episode alone, all manner of scenes arose that would have been hard to foresee while Dawson was on the books at Northampton. For example, the records are frustratingly incomplete, but surely this would have to be one of the only times a member of the England World Cup-winning squad of 2003 has been seen on the UKTV Food channel, sexing crabs (apparently, your “cock” crab has an altogether different flavour from your female).

The point of Mitch and Matt's Big Fish, as far as one can tell, is for Mitch and Matt to run up a rough-and-ready guide to the richness and potential appeal of the nation's indigenous seafood while calling each other “mate” as often as possible. They visit the quayside fish market in Brixham, Devon. (Mitch: “It's a pretty rock'n'roll environment, mate.”) They haul lobster pots out of Dartmouth Harbour. (Matt: “I'm chuffed to bits with that, mate.”) Then they get together round the cooker and make a simple, home-made hollandaise sauce. (Mitch: “I think we'd call that 'd' for done, wouldn't we?” Matt: “Good man. Cheers, fella.”)

There's a scene in the film Planes, Trains and Automobiles in which Steve Martin and John Candy become sleepily entwined with one another while sharing a motel room - only, upon waking, to explode out of bed and start talking randomly about football to convince each other of their unswerving heterosexuality. For some reason, the scene comes to mind a lot during Big Fish, while Mitch and Matt are bullishly shouting “mate” at each other while fussing over a teriyaki marinade. (Matt: “Like a bit of Asian fusion, me, mate. Not scared of that.”)

The banter and the bluffness would be easier to enjoy if they weren't so disingenuous. Dawson has proper culinary credentials. His Celebrity MasterChef victory, in 2006, was no flash in a non-stick pan. Indeed, the rugby man's thyme-roasted duck leg with sticky-onion marmalade remains a monument of the celebrity-challenge era and his crispy-skinned chicken breasts with garlic mashed potato and truffle cabbage are still fondly remembered wherever people gather to talk about food-related achievements by retired sportspeople in the televised context.

By those mighty standards, Mitch and Matt's Big Fish could be thought to represent a bit of a climbdown for Dawson - both in its execution and profile. (UKTV Food lies somewhere between Living and the off button.) But it's all television, one realises, and that's the main thing.

In the week's big election news, it was farewell to Andrew Castle, whose bid for Strictly Come Dancing glory in 2008 (incautiously endorsed by this column) bit the dancefloor after a toe-to-toe slug-out with Heather Small. Arlene Phillips had told the former British No 1 tennis player: “You just need to unleash the beast and let it go.” But alas Castle's beast remained leashed in a samba - perhaps even asleep under a sofa at home.

After the votes were counted, the smooth-talking GMTV host said he was “flat as a pancake” and missing the programme already. “Can I have a wild card?” he asked Claudia Winkleman in Strictly Come Dancing - It Takes Two, the nightly BBC Two debriefing. “That was the only way I ever got into Wimbledon.”

Alas, Strictly, unlike the All England Club, operates on the basis of a stringent meritocracy. There are no free rides at the celebrity-ballroom interface. Still, the manner of Castle's leaving, and the way in which he subsumed his personal disappointment in a perfectly pitched tribute to Ola Jordan, his professional dancing partner, were impeccable. I think we'd call that 'c' for class, wouldn't we? They can't teach that.