Iced Plum Tomato Soup with Baby Mozzarella and Basil

This eternally popular soup wasn’t originally made for the restaurant: it was a staple of the outside catering business. Mark Hix says we must have served it a thousand times before it finally appeared on the menu. It was an immediate success. It is simple to make but don’t be tempted to use anything other than ripe plum tomatoes or other well-flavoured ones. It is an intensely flavoured soup and therefore served i