I followed this recipe but changed a little.
Bread flour 58g
Whole grain flour 58g
Yeast 1/2tsp (original recipe is 1/16tsp)
Mix all the sourdough ingredients. Let it rest for at least 2 hours. Original recipe said let it rest for overnight. That’s why I increased yeast to 1/2 tsp.
Melted butter 20g
Salt 1 pinch
Blend all these ingredients in blender till paste.
Bread flour 306g
Whole grain flour 34g
Mix all the bread ingredients together into a dough. Let it rest for 30 mins.
Then fold in sourdough and walnut paste. Mix well into a big dough. Let it rise into 2 times big.
Preheat oven to the highest.
Knead it and press the air out. Let it rise again for another 40 mins. Cut the surface with pattern you like.
Turn oven to 230 degree C. Put in 1/4 cup water and let the water steam arise. Put bread dough into oven. Bake for 15 mins. Then take the water out and bake for another 25-30 mins. If the color too dark, cover with foil.