My first encounter with the delicacy known in Chinese as pi dan (“skin-eggs”), and in English as “thousand-year-old eggs”, was dreadful. Friends had invited me for dinner at a famous Hong Kong restaurant, and we were offered them, sliced in half with a dressing of ginger and vinegar, as a so-called appetiser. They leered up at me from the plate like the eyeballs of some nightmarish monster. Their albumens were a filthy, translucent brown, their yolks an oozy black, ringed with a layer of greenish, mouldy grey. About them hung a faint haze of sulphur and ammonia. I tried one, just to be polite, but was so aghast at its appearance that I found it hard to swallow, and I felt nauseous afterwards. To make matters worse, a slick of black slime from the yolk clung to my chopsticks, threatening to contaminate everything else I ate. I tried surreptitiously to wipe them on the tablecloth.

Since then, I have come to love pi dan, and I regularly inflict them on guests at my London dinner parties. A little psychological preparation generally helps. Think of them as the Chinese equivalent of blue cheese, I suggest to sceptical friends. Mouldy old milk is a pretty disgusting idea, but isn’t it delicious? I find that a blindfold can also be useful because it’s the appearance of the pi dan that is so off-putting, rather than their taste. And if you allow the ammoniac aromas to disperse before you serve them, your guests won’t suspect anything. “It tastes kind of...eggy,” says Stephen, when I feed him, blind, with a good slice of pi dan. “Nice, reminds me of mayonnaise,” says Sarah. It is only when they are allowed to open their eyes that they are revolted, and amazed.