Stir sugar, salt and farina slowly into scalded milk. Cook until thick, stirring constantly.
Add butter, nutmeg, prunes and the egg yolks, which you have beaten well. Turn mixture into a buttered baking dish.
Beat the egg whites until stiff and fold in the sugar, salt and vanilla. Spread this mixture over the batter and bake in a preheated 325° oven 15 minutes, or until the meringue is a delicate brown.