The mission

Normally something of a lager lad, Nicholas Barber is shaken by the challenge of mixing cocktails at Mash

I have to say, I was sceptical about this one. The editor had the idea that I should learn how to make cocktails, and thereby enhance my already uncanny resemblance to Tom Cruise. I wasn't keen. The thing is, my contempt for Cocktail the movie is matched only by my contempt for cocktail the beverage. I am, I'm not ashamed to admit, a lager man. I have never once paid for a Long Slow Comfortable Screw. Nor have I ever understood how a stick of celery could improve any drink. Or any meal, for that matter. And let's face it, cocktail- mixing is not exactly difficult. You just slosh a load of drinks together - and we've all done that at the end of a teenage party.

Still, I do as I'm told, and turn up at the fearsomely trendy Mash bar in central London (decor: Space 1999 with a twist of irony). There I meet Jamie. He knows more than 600 recipes off by heart - a fair proportion of which are award-winners that he invented - and he believes his creations to be little short of haute cuisine. I see his point. In time-honoured Delia fashion, there is an array of metal bowls behind the bar, each filled with prepared ingredients - grapes, strawberries, salt and pepper, even chocolate flakes. That's certainly a lot more food than there is in my kitchen.

And if the mark of a skilled profession is the fog of jargon that surrounds it, then cocktail concoction qualifies. Jamie shows me the Dispense Area and the Bar Station. He guides me round the Speed Rails, and introduces me to a Boston tin, a jigger, and a Hawthorn strainer. By the time I've got to grips with a Hamilton Beach blender, I'm a convert. I take back everything I've ever said about bartending. I squeeze into a Mash T-shirt, so my own shabby attire won't upset the customers, and our episode of Can't Cocktail, Won't Cocktail begins.

First Jamie teaches me the basics: how to pour liquor down a bar spoon; how to open a bottle of Champagne (hold the cork, twist the bottle). Next I learn not to be muddled by the difference between a muddled cocktail and a layered one. I nick my finger while slicing a lime, and nearly produce an impromptu Bloody Mary, but I've soon mastered the raspberry margarita and the Caipirinha. The piece de resistance is the B52: three tiers, orange on white on black, and when you put a match to the Grand Marnier, you get a blue flame on top. Truly, this is art: a sculpture you can drink.

Finally, I'm ready for some Tom Cruise-style fancy stuff, or to use the technical term, "flair". However, although Jamie obligingly juggles an ice cube and a glass, he refuses to let me have a shot, for the understandable reason that I've already had, well, so many shots. Just to test my newly acquired skills, you see, I've been sampling my cocktails as I've gone along. And what with Jamie being a professional, I've really had no choice but to knock back the ones he's been making, too. I'd call this Mission a partial success. I've barely grasped the basics of mixing cocktails, but I'm making excellent progress at drinking them