01 - In a large mixing bowl, whisk together the bread flour, active dry yeast, fine sea salt, and brown sugar until evenly distributed.
02 - Create a well in the center of the dry mixture and pour in the warm water and olive oil. Stir to form a shaggy dough.
03 - Turn the dough onto a floured surface and knead for 8 to 10 minutes until it becomes smooth and elastic.
04 - Gradually knead the chopped walnuts into the dough until they are evenly distributed throughout.
05 - Transfer the dough to a lightly oiled bowl, cover with a damp kitchen towel or plastic wrap, and let it rise in a warm place for 1 to 1.5 hours, until doubled in size.
06 - Deflate the dough gently and shape it into a round or oval loaf. Place it on a parchment-lined baking sheet or into a greased loaf pan.
07 - Cover the shaped dough and allow it to rise again for 30 to 40 minutes until puffed.
08 - Preheat the oven to 400°F (200°C) while the dough completes its second rise.
09 - Using a sharp knife, make several slashes on the top of the loaf to allow for expansion during baking.
10 - Bake the loaf for 30 to 35 minutes until the crust is deep golden brown and the bottom sounds hollow when tapped.
11 - Remove from the oven and cool on a wire rack completely before slicing.