Cut open the packets of tea and add them to the scalded heavy cream. Stir the mixture, then cover and steep the tea for about 8 minutes. The cream will darken to a tan color.

There’s a delicate art to brewing the Thai tea at ChaTraMue, the Thailand-based tea shop that’s been around since 1945. It starts with Thai tea leaves sourced from a farm in Chiang Rai. The ...