In a large bowl combine flour, yeast, salt, nuts and seeds, then add water.
Stir to combine and obtain a sticky dough.
Cover the bowl with a clean towel and let the dough rise at room temperature for for 12 hours (until bubbles appear on its surface).
Sprinkle a working surface with flour, transfer the dough on it, fold it once or twice and give it a ball shape.
Sprinkle abundantly the bowl with flour, place the dough inside, cover with a clean towel and let it rise for two more hours (it should double its size).
With about 20 minutes before the dough is ready, heat the oven at 220ºC/450ºF and place a cast-iron pot or a clay one into the oven, empty, to accumulate heat.
Remove the pot from the oven, carefully transfer the dough into it, cover with a lit and bake for 30 minutes.
Remove the lid and bake for 40 more minutes.
Remove from the pot and let cool for a 10 minutes before slicing.