"At Tonka, this dish is served topped with Shaw River buffalo curd. If you can't get buffalo curd, use yoghurt instead - the tang of either is a contrast to the richness of the curry sauce," says D'Sylva.
Note Healthy Boy soy bean sauce is available from select Asian grocers. Dried Kashmiri chillies are available from Indian grocers. Indian-style yoghurt is slightly sweeter than regular yoghurt and is available from Indian grocers; or substitute plain yoghurt.