Preheat oven to 400º. Place tomatoes in a single layer on paper towels; sprinkle with 1/2 tsp. salt. Let stand 30 minutes. Pat dry with paper towels.
Meanwhile, roll 1 pastry sheet into a 14-inch square on a lightly floured surface; place on an ungreased baking sheet. Cut 4 (12- x 1-inch) strips from remaining pastry sheet, and place strips along outer edges of pastry square, forming a border. Reserve remaining pastry for another use.
Bake at 400º for 14 minutes or until browned.
Sprinkle pastry with mozzarella cheese and next 3 ingredients. Top with tomatoes in a single layer. Sprinkle tomatoes with herbs and remaining 1/4 tsp. salt; drizzle with oil.
Bake at 400º for 14 to 15 minutes or until cheese melts. Serve immediately.