1. Start with the sourdough. To do this, mix the starter (active sourdough) with the rye flour and cold water in a glass jar and leave it on the counter covered at room temperature overnight for 15-16 hours.

2. When the sourdough is done, prepare the pre-dough (poolish) by mixing the yeast with the cold water in a second glass jar until dissolved, then add the wheat flour and mix well. Cover and let sit/rise at room temperature overnight for 14-15 hours.

3. The next morning, boil the potatoes in salted water until done, then peel and while still warm press through a potato ricer or mash with a potato masher. Cover and set aside.

4. For the main dough add the sourdough and pre-dough to the bowl of the kitchen machine. Add the wheat flour, salt, fresh yeast, beer, sugar beet syrup, roasted onions, and mashed potatoes. Season with some nutmeg, pepper, and paprika powder, and then knead everything for about 10 minutes until you get a nice and smooth dough – it will be quite soft and sticky, but that’s OK. Place the dough on a well-floured surface and fold it several times (with floured hands) over itself. To do this, grab the dough by the edges, pull it up, and then pull/fold it to the opposite side and then down. This process should help to build up some tension in the surface of the dough. Place in a well-floured proofing basket, dust with some flour, and let rise at room temperature for about 1 hour.

5. Preheat the oven along with a cast-iron pot (Dutch oven with a lid) to 460°F (240°C) for at least 45 minutes. When the dough has risen long enough, carefully remove the pot from the oven (it’s going to be very hot!). Place the dough inside the pot (the side that was on the bottom in the basket should now be facing up), score the top with a very sharp knife if desired, brush the sides of the pot with some water, then place the lid on top again and put it back in the oven. Turn the temperature down to 445°F (230°C) and bake for about 35 minutes, then remove the lid and bake for 15-20 minutes more. The bread is done when it sounds hollow when you know on the crust.