Soak dalia overnight in water. Sift whole-wheat flour and flour together on a surface and make a well in the center. Cream the yeast with sugar and little of water and pour in the well, sprinkle some flour and leave in a warm place until frothy.
Mix in the soaked dalia and all other ingredients except egg yolk and knead to a smooth dough. Keep in a warm place until doubled in size. Knead to punch out the air and divide into half and shape into loaves Place it in a baking tin and leave it to ferment some more.
Brush the loaves with egg yolk and bake in a pre-heated oven at 200 C for forty minutes. Allow it to cool before slicing and serving.