Thinly slice tomatoes and place in a single layer on a paper towel lined baking sheet. Sprinkle with about 1/2-teaspoon salt and set aside while preparing crust.
Preheat oven to 400 degrees.
Thaw puff pastry according to package directions; open sheet and roll out on a lightly floured surface into a 14-inch square. Place pastry on parchment sheet lined baking sheet or tart pan. Prick pastry every 1-inch using the tines of a fork. Bake 12-14 minutes or until puffed and lightly browned. Remove from oven.
Blot tops of tomatoes with a paper towel to remove excess moisture; arrange tomatoes on tart. Sprinkle with fresh herbs and remaining cheese. Bake 12-16 minutes or until tomatoes are wilted, cheese is melted and bubbly. Serve warm