Rosemary Focaccia with Olives

Preparation Pierce potato several times with fork. Microwave on high until tender, turning once, about 12 minutes. Cut in half. Scoop flesh into small bowl; mash well. Measure 2/3 cup (packed) mashed potato; cool (reserve extra potato for another use). Combine 2 1/2 cups flour, half of rosemary and 1 teaspoon salt in processor; blend until rosemary is chopped, about 1 minute. Add potato; blend in, using about 25 on/off turns. Combine 1 cup warm water and sugar in 2-cup glass measuring cup; sprinkle yeast over. Let stand until foamy, about 5 minutes. Stir 3 tablespoons oil into yeast mixture. With processor running, pour yeast mixture into flour mixture. Process until smooth, about 1 minute. Scrape dough out onto lightly floured surface. Knead until dough feels silky, sprinkling with more flour as needed, about 1 minute. Place dough in large oiled bowl; turn to coat. Cover with towel; let rise in warm area until doubled in volume, about 1 hour. Position rack in center of oven and preheat to 450°F. Brush large baking sheet with oil. Punch down dough; knead 30 seconds on lightly floured surface. Stretch or pat out dough to 12-inch round. Transfer round to prepared baking sheet. Press dough all over with fingertips to dimple. Brush with 1 tablespoon oil. Press olive halves, cut side down, into dough. Sprinkle with sea salt. Let rise until just puffy, about 20 minutes. Bake until golden, about 18 minutes. Serve warm or at room temperature.

Preparation Pierce potato several times with fork. Microwave on high until tender, turning once, about 12 minutes. Cut in half. Scoop flesh into small bowl; mash well. Measure 2/3 cup (packed) mashed potato; cool (reserve extra potato for another use). Combine 2 1/2 cups flour, half of rosemary and 1 teaspoon salt in processor; blend until rosemary is chopped, about 1 minute. Add potato; blend in, using about 25 on/off turns. Combine 1 cup warm water and sugar in 2-cup glass measuring cup; sprinkle yeast over. Let stand until foamy, about 5 minutes. Stir 3 tablespoons oil into yeast mixture. With processor running, pour yeast mixture into flour mixture. Process until smooth, about 1 minute. Scrape dough out onto lightly floured surface. Knead until dough feels silky, sprinkling with more flour as needed, about 1 minute. Place dough in large oiled bowl; turn to coat. Cover with towel; let rise in warm area until doubled in volume, about 1 hour. Position rack in center of oven and preheat to 450°F. Brush large baking sheet with oil. Punch down dough; knead 30 seconds on lightly floured surface. Stretch or pat out dough to 12-inch round. Transfer round to prepared baking sheet. Press dough all over with fingertips to dimple. Brush with 1 tablespoon oil. Press olive halves, cut side down, into dough. Sprinkle with sea salt. Let rise until just puffy, about 20 minutes. Bake until golden, about 18 minutes. Serve warm or at room temperature.