Crumble the fresh yeast into the lukewarm whey and stir. Crush caraway seeds, aniseed, coriander and fennel in a mortar or grind finely in a grinder. Put all ingredients (including walnuts and sunflower seeds as desired) in a kneading machine and work on the lowest setting for about 10 minutes to form a dough.
Then put the dough in a basket or bowl, cover with a tea towel and let rest in a warm place for about 1 hour until the dough has risen nicely.
Preheat the oven to 250 ° C and place a small bowl of water on the oven floor. Turn the dough out of the cooking basket and bake on a fireclay stone or baking sheet middle rack, top / bottom heat, for 10 minutes at 250 ° C, then reduce the temperature to 210 ° C and bake for about 50 minutes.