In the bowl of a stand mixer or in a large bowl, mix the sourdough, whole wheat flour, and 1 cup of the bread flour with the water. Set aside, covered, for four hours.
In a food processor, process the olives, sage, garlic and black pepper until the olives are in fairly small pieces. Set aside.
Add the remaining cup of bread flour to the mixer bowl along with the salt and the olive-sage-garlic-pepper mixture. Knead till the dough comes together. If your dough looks wet, add more bread flour, ¼ cup at a time. Your dough should be slightly sticky but not wet.
Continue to knead on medium speed or by hand for five minutes.
Remove the dough to a floured surface and knead into a smooth ball using your hands. Place in an oiled bowl, turning around once to coat the top with oil. Cover with cling wrap, and place in a warm spot for two hours. The dough will rise a little but it may not double at this stage.
Punch down the dough to form a circle. Roll into a log and press the seams together. Roll it a little. You can form a log-like shape, as I did, or shape into a boule.
Cover a cookie sheet with parchment paper, and place the loaf on the parchment. Dust on flour with a sifter and cover with a kitchen towel. Place in a warm spot for an hour or until the loaf has doubled in size.
In the last half hour of rising, preheat your oven to 450 degrees. If you have a baking stone or a pizza stone or unglazed ceramic tiles, place them in the middle rack of the oven.
Five minutes before you place your loaf in the oven, pour a cup of hot water into an oven-safe pan and place it on the lowest rack of the oven.
Take a very sharp or serrated knife or a sharp blade and score the loaf carefully, making one long, vertical slit. Take care not to lean too heavily into the knife or you will deflate the bread -- let the weight of the knife do the work. Carefully pick up the parchment sheet and place the loaf directly on the baking stone. If you don't have a baking stone, simply place the cookie sheet with the loaf into the middle rack of the oven.
After 10 minutes, lower the baking time to 350 degrees. Continue baking for another 45 minutes.
Remove the loaf from the oven and let it cool on a rack before you slice.