2) In a medium bowl, with a spoon, combine the prawns, mayonnaise, egg, breadcrumbs, chives, salt and black pepper. Mix well and then shape the mixture into 4 cakes, each about 3cm thick.
3) Place the cakes on the hot griddle and cook 3 minutes per side, flipping with a spatula, until cooked through. Remove from the griddle.
4) While cakes are cooking, in a small bowl, with a spoon, combine the mayonnaise and grain mustard. Mix well. Serve the prawn cakes with the remoulade spooned over the top.