Make the overnight starter by mixing together the sourdough, whole wheat flour and 1 cup all purpose flour. Mix well and let it stand overnight or for eight hours, covered, in a warm place.
Add the salt, water and olive oil and knead in the remaining flour, half a cup at a time, until you have a fairly loose batter that just comes off the sides of the bowl but does not gather into a ball.
Cover the bowl with a cling wrap and let the dough rise for 1 hour and 30 minutes.
Using a wooden ladle, turn the dough over on itself in the bowl gently about 9 or 10 times, trying not to deflate too many of the lovely bubbles that have formed.
Oil or spray with oil a large, 15-inch baking sheet with sides.
Pour the batter into the center of the sheet and, using a spatula or flat ladle, help it along so it nearly fills the pan.
Brush on some olive oil to keep the batter from drying, but don't cover it up with a towel or cling wrap-- both will stick to the dough.
Leave the baking pan in a warm place for an hour or until the dough has risen to fill the entire pan and has risen to the top of the pan.
About half an hour before you're ready to bake, preheat the oven to 400 degrees.
Make the toppings by smashing together the herbs, garlic, olive oil, black pepper and salt in a mortar and pestle. You can use a food processor, but in that case don't add the olives. Process the herbs, oil, garlic, salt and pepper into a coarse paste. Smash the olives with a heavy knife, and then mix into the herb-oil mixture.
Smear the olives-garlic-herb mixture on top of your risen focaccia as evenly as you can without deflating the dough.
Bake in the preheated oven for 25 minutes or until the top is lightly golden and the bread has started to pull from the sides. One way to tell your bread is done is to press it slightly, and if it springs back, you know it's ready.
Let the bread cool on a rack at least 30 minutes before cutting and serving.