What is it they are hating, this group of office co-workers on their Christmas lunch in a high-street chain-restaurant (book early to avoid disappointment, party's welcome)? They are hating, for a start, the fact that they are having to pretend not to hate each other for at least an hour, and the party hats are making it worse, and the women are hating Bill for his increasingly blatant sexism although they are still offering him decidedly more smiles than they are affording Gretchen, the friendly 19-year-old work trainee from Delft who has arrived cursed with a waist and cheekbones and the like; and one of the (non-Gretchen) women is really hating herself for still quite wanting to sleep with Bill.

Most of all, however, they are hating the food. Which is, in fact, the thing that's making them do the hating, though they don't realise it. When the fierce fight takes place - and, statistically, there are likely to be upwards of 1,200 such fights this Christmas, three or four of them fatal - the defendants will blame it on the drink. Wrong. This is what is to blame:

Exhibit one: 'Three slices of real turkey breast.'

The slices are possessed of a uniformly circular quality. This temporarily confused the defence, which had hitherto been ignorant of the fact that a turkey was a long tubular boneless self-slicing creature, and ignorant also of the concept of meat which, when dropped, bounces. Confusion ended when scientific analysis (appendix F) demonstrated that the substance was not, in fact, 'turkey breast' but a compound comprising a) the floor-sweepings of a Shanghai abbatoir from 1960, one year before the (even then admittedly lax) hygiene restrictions were imposed; b) compressed flesh from the noses of the 18 tramps dragged from London's Regent's Canal between 1995 and 2000; c) a 'moistening agent' later identified, during plea-bargaining by a member of the Christian Brothers, as 'the gummy stuff we stored in vats which we used to scrape off the kids' eyelids just after they woke up, especially the dwarves'; and d) what the scientists described as 'really neat clever plastic binding agent, might blow your fingers off so just be careful.'

Exhibit two: 'Home-made Cranberry Jelly.'

Here, the defence can do no better than quote from the labelling on one of the individual sachets recovered from the scene.

'Lovingly Packed for the Convenience of our Valued Customers and in particular those who Yearn to break a few fingernails and then spend five sobbing minutes jabbing at a Tiny square Inch of recalcitrant plastic with the blunt tines of a fork before going home with the Crotch of the trousers matted in Sticky Red Seedy Globs especially Aroma'd to attract the determined noses of Dogs and Mad Tube People. 'P.S. Do not Eat.'

Exhibit three: 'Tasty chipolatas.'

This description was found wanting in that there were 10 chipolatas for 10 people, so it should have been 'tasty chipolata'. Even then the tastiness could not be verified, none of the forensic staff being able, despite increasingly ingenious and (frankly) desperate attempts, to devise a test which did not involve the process of actually putting the thing inside a mouth and tasting it. The exhibit is two inches long and striped pink and black, the striping having been achieved by, at one stage, wrapping the sausage in a rasher of bacon. The traditional purpose of this is, it would appear, to protect half of the sausage from being in any way cooked during its sojourn in the microwave, and then let the bacon drop onto the floor on the way to the table, there to slide under chair legs and waiters' feet and generally imbue the floor with a greasy ambience reminiscent of Christmas in a Shanghai abbatoir in 1960.

Exhibit four: 'Chef's oven-roast potatoes.'

These would appear to be, in fact, bullets covered in fluff. Still awaiting return of ballistics report from firearms laboratory at Aldermaston, which, incidentally, has asked the court's indulgence in claiming firsts rights if the exhibit turns out to be unpatented.

Exhibit five: Unidentified semi-liquid substance.

The closest technical classification for this colourless wash, featuring a number of heavier lumps and a fierce odour of fish, was 'gloop'. Its purpose was unclear until, in the kitchen, two tins of powdered colouring substances were discovered, one yellow and one brown, and it was understood that the chef's habit was to add a spoonful of each to the exhibit depending on whether gravy or custard was being called for. The tragic events of that night appear to have stemmed, in part, from a misunderstanding at this stage of the food preparation process. The defence rests its case.