First make the spicy paste. Place all the ingredients in a mixing bowl and stir well to combine. This will keep for a couple of weeks in an airtight container.
Place about a tablespoon of the spicy paste in a large frying pan and heat over a medium heat. Add the prawns and shake the pan to cover the prawns in the paste. When the prawns are warmed through add the butter and a splash of warm water to make a sauce. Sprinkle over some fresh coriander and serve with finger bowls (this dish is very messy).