Scrub potatoes with vegetable brush under cold running water. Peel. Cut into 1-inch pieces. Place in medium saucepan and add cold water to cover. Over high heat, bring to boiling. Reduce heat to medium. Cover and simmer until potatoes are tender, about 12 to 15 minutes. Drain very well. Return potatoes to pan and mash. Let stand a few minutes to cool.
While potatoes cook, in large bowl combine flour, rosemary, thyme, basil, oregano and salt. Mix well. In small bowl, stir together water, yeast and sugar. Add 2 tablespoons of the oil and let stand until frothy, about 5 minutes.
Pour yeast mixture into the saucepan with the potatoes and mix until smooth. Pour potato mixture into the flour mixture and stir until mixture comes together to form a soft dough. Add a tablespoon or two of additional flour, if needed. Turn out onto lightly floured surface and knead until the dough is smooth and elastic, about 5 to 6 minutes (or mix on mixer with a dough hook). Coat a large bowl with cooking spray. Add the dough, turning to coat all sides. Cover with plastic wrap and let rise in a warm place (about 85°) free from drafts until doubled in size.
Preheat oven to 425°. Coat a 15-inch x 10-inch jellyroll pan with cooking spray.
Turn the dough out onto the prepared pan and gently press to fit. Cover with plastic wrap and let rise in warm place for 30 minutes.
Gently brush top of dough with the remaining 1 tablespoon oil. Top with tomatoes, cut side down, then sprinkle with cheese and coarse salt. Bake 20 to 22 minutes or until golden. Remove from the oven and transfer to a wire rack. Let cool at least 10 minutes before cutting. Serve warm or at room temperature.
Nutritional Analysis per serving: 178 calories, 5 g protein, 30 g carbohydrates, 4 g fat, 1 g saturated fat (21% of calories from fat), 1 mg cholesterol, 2 g fiber, 258 mg sodium