‘I think I’ll have the steak and chips’, said my friend. ‘You’re darn right you will’, I told him (writes Douglas Blyde). Café de Paris only offers one savoury option: tender entrecôte with brittle matchstick chips and fresh salad. But what makes the formula memorable is the rich butter sauce, which gradually floods the strip of steak as it melts, its enticing aroma melding with the tabletop burner. Arguably, this has done more for butter’s renown than Marlon Brando.

The secret recipe, goes the legend, has been held by just five people and actually predates the existence of this inconsequential looking Geneva brasserie by a decade. Invented in 1930 by Mr. Boubier, owner of ‘Coq d’Or’ restaurant, the butter didn’t achieve much fame until his daughter shared the secret with her husband - the owner of Café de Paris. Sources state that for some years it was near impossible to get a table there, and even today our reservation occurred close to midnight.

Although I was nonchalant about my first chip dip into the Béarnaise coloured, unguent sauce, I was soon disgracing myself, even dipping my finger into it. A fellow diner was so disgusted by this, that they slid the plate away. Or so I thought. They actually wanted to monopolise it to do just the same. Part of the problem is its fleeting richness – another fix is needed fast. At 41 Swiss Francs (£30) a meal, this could become an expensive addiction.

Naturally, the Internet is writhing with well documented attempts to mimic its make-up. Some chefs insist it includes Pernod and finely minced, sieved chicken livers. I doubt the presence of poultry, but I did sense many umami-rich anchovies, as well as shallots, citrus and tarragon

Today, under the ownership of Mr. Vouillamoz, the restaurant ships the sauce under licence to restaurants from the Mediterranean to the Middle East. Perhaps I will try it elsewhere, although I doubt it will taste quite the same as our feast approaching midnight in the absolutely un-chic but iconic and curiously perfumed Swiss brasserie...

Café de Paris
Rue du Mont-Blanc 26, Geneva
www.cafe-de-paris.ch