All the best fritkots follow these rules,although these days they buy pre-cut chips – fresh (not frozen),delivered daily and discarded at the end of that day if not used. They double-fry them in 100 per cent beef fat,which is changed regularly. But the result depends critically upon how the alchemy is performed. Much can go wrong in the process,producing either perfection or cruel disappointment:pale,flavourless,floppy or undercooked chips,with an unpleasant aftertaste.

Traditionally,frites are served piping hot in a card or paper cone with a large dollop of mayonnaise on top. It's a meal in itself,but you can add any of the customary meat products,such as sausage-like fricadelles and cervelas,boulettes (meatballs),brochettes,satay,hamburgers,hot dogs – and often a carbonnade (a sweet beef stew cooked in beer). Instead of mayonnaise you can choose any of a dozen or so sauces:cocktail,pili-pili (chilli),tartare,garlic – you name it.

Fritkots also serve soft drinks and beer,and sometimes wine. All in all,you can dine out,sitting on a bench,for about €7. Frites should cost about €2 for a standard portion or €2.50 for large,plus 50¢ for the sauce.

More information about how to indulge that frites fetish can be found atvisitbrussels.be andbelgiumtheplaceto.be.

Five top fritkots

1 Top comes Frit Flagey in Place Eugene Flagey,Ixelles. When Place Flagey was revamped recently,its fritkot was threatened with extinction but saved by a public petition;this,after all,was the fritkot immortalised by the great Jacques Brel in his songMadeleine. Thierry van Geyt is now in charge,and he does his work with pride and diligence. I would give him a perfect score — the gold standard by which all others can be measured. (10/10)

2 In the city centre,the fritkots in the Place de la Chapelle — at the top of the folksy Marolles district and below the Place du Grand Sablon — serve frites that are well above average. (8/10)

3 If you don't wish to stray much beyond the Grand-Place,Friterie Tabora at 2 Rue Tabora claims to use traditional methods and has 42 years of frying experience. (7/10)

4 In the western district of Saint-Gilles is the highly rated fritkot of the Barriere de Saint-Gilles (it's actually in the Avenue du Parc). Nothing particularly glamorous here — it's jammed up against a wall on a busy street and next to bins and a bus stop. Frites:good,but I was not wholly convinced. (7/10)

5 The famous Maison Antoine in the middle of Place Jourdan,across the Parc Leopold from the European Parliament,was established in 1948 and has evolved into a kind of chalet serving a wide variety of meal-size snacks. I am not alone in thinking that the frites here fall well short of the Belgian ideal. But it is a popular location,in part because neighbouring bars allow clients of Maison Antoine to bring along their chips to drink with their beer — look for signs saying"Partenaire de la Maison Antoine — frites acceptees". (6/10)

Where to buy them

According to the organisers of the year-long food festival called Brusselicious 2012 (of which the Tram Experience is part),the best fritkots in Brussels are not in the centre. The Brusselicious Fritkots Walk is not a walk at all,as all 10 of the recommended fritkots are spread around and outside the city centre.

The fritkots have,in effect,followed the money. The well-to-do of Brussels live in the suburbs,and that's where the fritkots can earn their keep. For tourists,the most convenient on the list are in the districts of Saint-Gilles and Ixelles close to the Horta Museum and art nouveau walks,and another in the EU area,close to the museums in the Parc du Cinquantenaire.

But I don't entirely agree. I rate at least two city-centre fritkots highly. At the far right is my guide to five of Brussels's best and most conveniently located fritkots.

Telegraph,London