1. In a small bowl combine yeast and 1/4 cup warm water (not more than 110 degrees) until dissolved. Let stand 5 minutes, until creamy, then stir well.

2. In the bowl of an electric mixer fitted with the dough-hook attachment, combine 1 1/2 cups all-purpose flour, the whole-wheat flour, and 1/2 teaspoon salt. Make a well in the center of the dry ingredients. Add the yeast mixture, 2 tablespoons olive oil, and 3/4 cup warm water (not more than 110 degrees). Mix until the dough is smooth and elastic, about 4 minutes, adding only enough of the remaining 1/2 cup all-purpose flour to make a very soft dough. Form the dough into a ball, and place into a large, oiled bowl, turning to coat.

3. Cover with a kitchen towel, and let rise in a warm spot for 1 hour, or until the dough has doubled in size.

4. Meanwhile, heat 2 tablespoons olive oil and butter in a large skillet over medium-low heat. Add onions and garlic cloves, and cook until they begin to soften, stirring often, about 20 minutes. Add balsamic vinegar, sugar, 1 teaspoon salt, and black pepper, and cook until golden brown, stirring often, about 50 minutes. Set aside.

5. Heat 1 tablespoon olive oil in a medium skillet on medium-high heat. Add sausage, and cook until browned on all sides, about 10 minutes. Remove from heat, and slice into 1/4- to 1/2-inch rounds. Set aside.

6. Heat oven to 400 degrees. Brush two baking sheets with olive oil, and set aside. Punch dough down, divide in half, and form each half into a ball. Roll one half of dough into a circle about 12 inches in diameter, keeping other ball covered with plastic wrap while working. Roll out second ball of dough, and transfer dough rounds to baking sheets. Brush the top of each dough round with olive oil. Divide onions in half, and spread a layer on each crust. Sprinkle the sausage on top of each crust, and dot each pizza with half the goat cheese. Bake until crusts are golden brown, about 15 minutes. Sprinkle with salt, pepper, and herbs. Slice the pizzas into small wedges, and serve immediately.