Dissolve salt, sugar and yeast in the warm water or milk, add an egg, flour, butter and knead dough. Divide into 10 pieces, roll out into flat cakes, center with grated cheese. Spread the stuffing evenly, leaving about 0.5 inch along the edges. Make up and crimp the edges, shaping a kind of barquette. Bake over 448 F° (220 °C) until half ready, then center with a butter bar, pour an egg apiece, and bake more egg white is thick, and then serve.