Weigh your flour; or measure it by gently spooning it into a cup, then sweeping off any excess. Combine all of the ingredients except the nuts, and knead — by hand, mixer, food processor or bread machine — until smooth., Place the dough in a lightly greased bowl and let it rise, covered, for 1 hour, or until it's doubled in bulk., Turn the dough out onto a lightly greased surface and gently but thoroughly knead in the walnuts. This will seem like messy work at first (the nuts will keep falling out onto the work surface), but persevere — eventually they'll stay where they belong., Divide the dough in half, and shape each half into a ball. Place the balls on a lightly greased or parchment-lined baking sheet, and let them rise, covered, for 45 minutes, until they're quite puffy, though not necessarily doubled in bulk., Preheat the oven to 425°., Uncover the loaves, and bake them for about 25 to 27 minutes, until they're golden brown. Remove the loaves from the oven, and transfer them to a rack to cool., Cool the loaves before slicing. Store, well-wrapped, at room temperature for three days, or freeze for up to three months.