For the wholemeal bread, mix rye flour and groats together in a bowl. Make a well in the center, crumble the yeast into it, add sugar and 100 ml of water and mix together with a little flour.
Cover the mixture and let it rise at about 220 °C for 15 minutes. Add the remaining water, sourdough and salt and knead everything into a smooth dough.
Now let the dough rise again, covered, for 60 minutes. Add 70 g of each of the 4 grains and knead well. Form 2 round loaves from the dough.
Brush the breads with water and cover half with sunflower seeds and half with pumpkin seeds. Press the seeds down a little.
Place the breads on a floured baking sheet and let them rise again, covered, for 30 minutes. Preheat the oven to 200 °C, fill an ovenproof soup bowl with water and place in the oven.
Bake the loaves in the preheated oven for about 1 hour. Then cool well and let rest for a few hours (at least 8 hours).