Potato Rosemary Bread

INGREDIENTS

• :
• 1¼ cups (7 ounces) biga (recipe follows)
• 3 cups plus 2 Tablespoons (14 ounces) unbleached high-gluten or bread flour
• 1½ teaspoons (.38 ounce) salt
• ¼ teaspoon (.03 ounce) black pepper, coarsely ground (optional)
• 1¼ teaspoons (.14 ounce) instant yeast
• 1 cup (6 ounces) mashed potatoes
• 1 Tablespoon (.5 ounce) olive oil
• 2 Tablespoons (.25 ounce) coarsely chopped fresh rosemary
• ¾ cup plus 2 Tablespoons to 1 cup (7 to 8 ounces) water, at room temperature (or warm if the potatoes are cold)
• 4 Tablespoons (1 ounce) coarsely chopped roasted garlic (optional)
• Semolina flour or cornmeal for dusting
• Olive oil for brushing on top
• 2½ cups (11.25 ounces) unbleached bread flour
• ½ teaspoon (.055 ounce) instant yeast
• ¾ cup plus 2 Tablespoons to 1 cup (7 to 8 ounces) water, at room temperature)