Edward Van Roy's Siamese melting pot: Ethnic minorities in the making of Bangkok is a tour de force and one of the most important books on the history of Bangkok and late-modern Thai history ever to be published. It is clearly written and presented, it provides excellent maps, and brings to light little-known sources and surprising facts about the history of the most iconic neighbourhoods in the city. It exposes the histories of various Muslim, Mon, Lao, Vietnamese, Chinese, European, Indian, and other communities in late Ayutthaya and Bangkok, as well as highlights various ways of seeing Bangkok as a feudal city, a vibrant port-city, or a galactic polity. Van Roy also reveals the complexities of defining ethnicity and class in Bangkok's changing neighbourhoods. In this review article I will look closely at two issues Van Roy exposes that need some theoretical and critical interrogation: the ‘galactic polity/mandala’, and ‘ethnicity’. Then I will provide a short vignette about the Chettiar community in Bangkok and the idea of Hinduism in Bangkok history that both supports and supplements Van Roy's excellent research. I write this not to discount or criticise Van Roy's monumental achievement, but because I believe a book this important to the field deserves serious attention and engagement.