Chances are that you've heard this one, but, as parents everywhere are getting used to squeezing sandwiches into brooddozen - sandwich boxes - now that the new school term has started, the joke does have a topical touch to it, though only just.

So there were these three bouwvakkers having their lunch break up on a skyscraper with their brooddozen on their knees and their legs dangling from a girder. One was from Flemish Brabant, one from Ghent and one from Limburg (which would normally involve the three dialects, but I'll ignore that here).

You may have worked out that the joke is going to be about the Limburgers, who in fact have a tendency to speak in an unrushed fashion, which some people interpret as a sign of mental slowness.

So on with de mop. The Brabander complains as he opens his brooddoos: "Weer dezelfde boterhammen met kaas - Again the same cheese sandwiches." He's so fed up, he says: "Als ik morgen weer kaas meeheb dan spring ik van deze stelling - If I have cheese again tomorrow, I'll jump from this scaffolding."

Being a classic joke everything happens in threes, so the Gentenaar says the same about his salami sandwiches and the Limburger about his chococovered bread. Fast forward, and the next day the trio lies dead 20 storeys down.

This being such an unusual tragedy, the three bouwvakkers are buried together, which gives the weduwen - widows - the chance to commiserate. "Had onze Kevin nu gezegd van de boterhammen met kaas, had ik andere gemaakt - Had our Kevin said something about the cheese sandwiches, I'd have made different ones," cried the Brabantse weduwe. Ditto de weduwe van Gent.

The Limburgse weduwe joined the wailing by praising her husband: "En mijnen Gerard liet mij nooit zijn boterhammen maken - And my Gerard never let me make his sandwiches. Hij stond erop dat hij ze zelf smeerde - He insisted on making them himself."

Well, I think I got the parts in the right order, and hope I haven't offended any Limburgers, who are all above average and live in the best part of the country.

Though I'm left wondering if boring sandwiches really tipped the three over the edge, or was there another reason? It might be interesting to know which workmates witnessed all this. But there, I'm spoiling the joke.