Beat the egg yolks and sugar until thick, add the flour, salt and enough milk to make a thick batter. rest for a quarter of an hour. Mix in the blueberries. Stir in the stiffly beaten egg whites of the 5 egg whites.
Heat fat in a frying pan, pour in the batter by tablespoonfuls, spreading a tiny bit apart. Bake the palm-sized cookies until brown on both sides, sprinkle with sugar and serve on the spot.