The night before you want to bake, do three things:
Put the dates in a big bowl and cover them with boiling water. Let them sit on the counter until the morning.
Break the walnuts into small pieces and dry roast them in a frying pan. Remove them as soon as you can smell them and let keep them until the morning.
Melt the butter and then leave it to cool completely.
In the morning:
Drain the water off the dates into a separate bowl. Make sure you keep the liquid!
Weigh the date liquid. If it is less than 600 grams, top it up with water to reach 600 grams. If it is more than 600 grams, pour some away to get to 600 grams.
Measure the flours into a big bowl and make a well in the centre. Measure in the yeast and cover it with enough of the liquid to fill the well. Flick flour on the water to cover it, and leave it for an hour.
After an hour, add all the other ingredients, EXCEPT the walnuts.
Mix everything together and then scrape it onto a non-floury surface. Knead for 10 minutes by hand (you can also do this by machine on the lowest speed). The dough is very soft and sticky but don't add more flour. A scraper will help if you are hand kneading.
Once kneaded, put the dough back into the bowl and cover it with cling film or a shower hat. Let it rest for 30 minutes. After 30 minutes, squash in the walnuts to make sure they are evenly distributed. Cover the dough again and let it rest for 2 hours.
Scrape the dough out onto a non floury surface. If you are making loaves, divide it in two. Shape the dough into two sausages and place them in greased tins. If you are making buns, divide the dough into pieces that weight about 75 grams each. Shape them into tight balls and transfer them to the baking tray lined with parchment.
Cover the dough and let it rest for 45 minutes.
Preheat the oven to 400 degrees.
Pop the dough in the oven and bake for 45 minutes. Check it after about 20 minutes and if they are getting too brown, cover them with non stick baking parchment.
Remove and let cool completely on a wire rack.
Enjoy!