Soften butter at room temperature. Dissolve in the yeast and sugar in water. Let mixture rest for about 5 minutes, until the yeast is foamy. Then mix this together with flour, salt and butter.
Knead dough and then lightly cover with oil in a bowl and let rise until doubled in size. This will take about 1 1/2 to 2 hours.
Preheat oven to 220 C (425 F). Shape bread into 2 loaves. Mix the egg white and salt together and brush glaze over loaf. Cut a slash line across each loaf. (This will help the bread release steam from the bread while baking and prevent it from exploding.) Sprinkle with seeds and slash top of dough with a knife. Bake for 20 minutes, then reduce the oven temperature to 180 C (350 F) and bake for 10 minutes or more, or until it sounds hollow when tapped on the base.