Pound all the spice paste ingredients in a mortar with a pestle. Or use a blender to process the ingredients, adding
Heat the oil in a wok and, when hot but not smoking, add the spice paste. Cook over medium heat for about 10 minutes, or until fragrant. Add the prawns and cook for a minute, then add the palm sugar, sea salt, coconut cream and tamarind water and simmer for a further 1–2 minutes, or until the prawns are cooked. Squeeze the lime juice into the wok, transfer the prawns to a plate and pour the sauce over to serve.