Vitello tonnato. Pronounce it, as an Italian would, trippingly off the tongue. Translate the traditional dish into English — veal with a tuna-flavored mayonnaise — and that initial mellifluous charm fades fast.

“It’s such a delicate dish, but such specific, strong flavors,” British chef Ruth Rogers said. “Once you start describing it, it becomes more complicated than it is.” That’s why, on the menu of London’s River Cafe, this antipasto from Italy’s Piedmont region comes with no description. It probably doesn’t need one; she’s been serving it there, unchanged, since 1987, when she opened the restaurant with Rose Gray .