1) Combine the starter, water, and 3 cups of the flour. Beat vigorously.
2) Cover, and let rest at room temperature for 4 hours. Refrigerate overnight, for about 12 hours.
3) Add the remaining ingredients, kneading to form a smooth dough.
4) Allow the dough to rise, in a covered bowl, until it's doubled in size, about 5 hours.
5) Gently divide the dough in half; it'll deflate somewhat.
6) Gently shape the dough into two oval loaves, and place them on a lightly greased or parchment-lined baking sheet. Cover and let rise until very puffy, about 2 to 3 hours. Towards the end of the rising time, preheat the oven to 425°F.
7) Spray the loaves with lukewarm water.
8) Make two fairly deep horizontal slashes in each; a serrated bread knife, wielded firmly, works well here.
9) Bake the bread for 25 to 30 minutes, until it's a very deep golden brown. Remove it form the oven, and cool on a rack.