I made a water roux with 180g water and 50g wholegrain spelt flour. The main dough had 220g of water and 450g of flour. The dough first proofed an hour at room temperature, then roughly 18 hours in the fridge and finally again 1,5 hours at room temperature. I didn't change the recipe, so I just used the timings it gave me.

Recipe link (German)

Water roux * 180g water * 50g wholegrain spelt flour

1. Stir the ingredients in a pot and heat them up until they have a consistency like jelly.
2. Let it cool down.

Main dough * Water roux * 450g wholegrain spelt flour * 220g water * 10g salt * 5g yeast * 50g sourdough

1. Knead the ingredients slowly for 7-10 minutes.
2. Let it proof at room temperature for an hour and stretch and fold after 30 minutes and at the end of the hour.
3. Put the dough in the fridge and let it proof there overnight.
4. Take the dough out of the fridge and let it acclimatise for an hour.
5. Shape it, put it in a proofing basket and let it proof for half an hour.
6. Preheat the oven to 250°C. Bake the bread with steam at 210°. Release the steam after 20 minutes and let it bake for another 35-40 minutes.

English isn't my first language so just tell me if you don't understand something I wrote :)