In a food processor, combine prawns, scallions, cornstarch,egg white, garlic, sesame oil with salt and pepper, and pulse until it forms a paste.
Cut off the crusts of your bread slices anddivide the prawn paste evenly between 2 sandwiches. Clean off the sides, brush theoutside with melted butter and bake at 180C / 350F in an airfryer for 15-20minutes or until the prawn paste is fully cooked. You could also deep fry (justomit the butter) or bake in the oven.
Sauce: 2 parts sweet chilli sauce, 3 parts kewpiemayo.