Teh talua (egg tea)

In the lapau coffee shops of Bukittinggi, Payakumbuh and Padang, the sound of a spoon or a small whisk clattering against a glass means someone has ordered teh talua. A raw egg yolk, traditionally from a free-range kampung hen or a duck, is whisked with sugar until thick and almost white, strong hot tea is poured on from a height, and a wedge of lime goes on the side. Minangkabau men drink it in the late afternoon or evening as a pick-me-up after work in the fields. It comes out with a creamy, caramel-coloured body under a deep layer of foam, rich like a light custard, with the lime cutting any eggy edge. The common mistake is whisking too little: the yolk stays yellow, the tea curdles it in strings and it smells of egg. Beat until the yolk has doubled in volume and falls in a thick ribbon. Use pasteurised eggs for anyone pregnant, babies and small children, older people or anyone unwell, as the yolk is only lightly warmed. Some lapau add condensed milk; this one is dairy-free. It contains caffeine. Chef's tip: pour the tea in a thin stream from high up while still stirring, to build the tallest foam.