Put the white flour in a large enough bowl and make an indentation in the center. Stir the yeast with the sugar until liquid and form into the indentation. Dust with a little flour.
Coarsely crumble the walnut kernels. Dissolve the salt in the lukewarm water. Add the milk. Tree nuts and water mixture to the flour form. Meanwhile, knead everything for eight to ten minutes to a smooth dough. Cover the dough and let it rise in a warm place for about 1 hour.
Knead the risen dough again briefly. Shape into a round loaf and place on a baking sheet lined with parchment paper. Let rise again for 15 minutes.
Preheat the oven to 220 degrees.
Brush the bread with egg yolk. Then score deeply with a sharp kitchen knife in a grid pattern. Place in the oven on the second rack from the bottom and bake for 40 to 45 minutes.