Peel and devein the prawns, making an extra deep and long incision to serve as a pocket for the stuffing. Combine the anchovy paste, butter, bread crumbs, lime juice, onion juice and pepper. Refrigerate for 30 minutes.
To make the batter, sift the flour and salt into a bowl. Make a well in the centre and add the butter, beer, and the yolk of the egg. Mix quickly and thoroughly, and set