Peel and wash the potatoes and cook in salted water for about 25 minutes. Crumble the yeast and dissolve it in 100 ml of lukewarm water. Mix the flour, 2 teaspoons of salt and coriander powder or caraway seeds. To press a hollow in the middle. Pour in the yeast water and mix with a little flour to make a pre-dough. Cover and let rise in a warm place for about 15 minutes.
Drain the potatoes, let them steam and mash them with a fork so that there are no more lumps. Heat the 300 ml milk and 200 ml water. Add the milk mixture and potatoes to the pre-dough. Knead everything well. Cover and let rise for 1 - 1 ½ hours. Knead the dough. Shape into a loaf on a little flour. Place on a baking sheet lined with baking paper and let rise for another 10-15 minutes. Bake in the preheated oven (electric stove: 225 ° C / convection: 200 ° C / gas: level 4) for about 45 minutes. Cover with baking paper after 30 minutes. Do a chopstick test, but be careful, the crust is a little harder.