Foi Thong — Golden Egg Threads / ฝอยทอง

Central Thai (royal court) — Portuguese introduction via the Ayutthaya court; these five egg sweets (foi thong, thong yip, thong yod, sangkaya, met khanun) are collectively called khanom che wang

Foi thong (golden threads) is one of five Portuguese-influenced Thai egg sweets introduced to the Siamese court in the 17th century, attributed to Marie Guimar (Dona Maria Guyomar de Pinha), a Japanese-Portuguese woman at the Ayutthaya court. Duck egg yolks are beaten, strained, then poured in a thin stream through a fine-hole sieve into a simmering jasmine-flower-infused palm sugar syrup. The egg threads set immediately in the hot syrup and are lifted out as delicate, hair-thin golden strands. The technique requires a steady hand, the correct sugar syrup concentration, and a deep understanding of egg behaviour at heat. Foi thong symbolises long life and prosperity in Thai food culture and is a mandatory element at Thai wedding banquets.

• Portuguese fios de ovos is the direct ancestor — foi thong is essentially identical; Japanese kinshi tamago uses egg threads in a savoury context; the Portuguese influence spread the same egg thread technique to Brazilian pão de ló de fios.

Foi thong's appeal is almost entirely in the technique made visible — the impossibly thin, perfectly uniform golden threads represent the pinnacle of Thai confectionery craft, and their beauty is inseparable from the skill required to make them.