1. Dissolve yeast in 3/4 cup warm water in a small bowl; let stand 5 minutes or until bubbly. Weigh or lightly spoon flour into dry measuring cups; level with a knife. Combine flour, salt, and 1/2 teaspoon pepper in a large bowl; make a well in center of mixture. Add yeast mixture to flour mixture; stir just until moist. Add oil, and stir until a dough forms. Turn dough out onto a lightly floured surface. Knead until smooth and elastic (about 10 minutes). Place dough in a large bowl coated with cooking spray, turning to coat top. Cover and let rise in a warm place (85°), free from drafts, 1 hour or until doubled in size. (Press two fingers into dough. If indentation remains, dough has risen enough.)
2. Punch dough down; cover and let rest 5 minutes. Roll dough into a 16 x 11–inch rectangle; place dough on a jelly-roll pan coated with cooking spray. Cover and let rise 1 hour or until doubled in size.
3. While dough rises, arrange tomato slices in a single layer on several layers of paper towels; cover with additional paper towels. Lightly press down occasionally.
4. Preheat oven to 375°.
5. Arrange tomato slices over dough. Sprinkle evenly with cheese. Bake at 375° for 28 minutes or until lightly browned. Remove flatbread from pan; cool 5 minutes on a wire rack. Sprinkle with chives and parsley. Arrange basil over flatbread; sprinkle with additional pepper, if desired.