Maurizio Morelli, the Roman chef at Latium, the Italian restaurant near Oxford Street, has created a successful alternative to the “signature dish” of which so many chefs and restaurateurs dream.

It would be extremely difficult to try to calculate how much profit and publicity dishes such as the spinach soufflé at Langan’s Brasserie or the roast duck at Le Tour d’Argent in Paris have generated for these restaurants since they first appeared on the menu and have proved too popular ever to be taken off.