First mix the 3 eggs and one egg white with the mixer. The yolk is needed at the end. Dissolve the sodium bicarbonate in the yogurt. Add the warm, dissolved butter. Then the crumbled sheep`s cheese (larger pieces can also be used) and finally the flour. Place the dough on a lightly greased baking sheet like a flat cake and decorate with 2 forks. Brush the dough with the egg yolk and bake at 150 ° C for about 40-50 minutes.