Tomato Mozzarella Tart

olive oil
1/2 pkg frozen puff pastry sheets thawed
8 ozs mozzarella cheese grated
1 1/2 lbs plum tomatoes
1/2 c Parmesan cheese freshly grated
1 tbsp olive oil
1 tbsp chopped thyme or 1 t. dried crumbled

Position rack in center of oven and preheat to 375 degrees. Brush 9x13 baking sheet lightly with olive oil. Roll out pastry sheet on lightly floured surface to 16x12" rectangle. Transfer pastry to prepared pan and gently press into place. Trim edges of pastry, leaving 1/2" overhang. Crimp edges. Pierce crust all over with fork. Bake until golden brown, piercing with fork every 5 min to deflate if necessary, about 15 min. Sprinkle crust with mozzarella and set aside. (Can be prepared 4 hours ahead. Let stand at room temperature.) Increase oven temperature to 425 degrees. Blanch tomatoes in large pot of boiling water 20 seconds. Drain and cool slightly. Peel and core tomatoes. Cut into thin rounds.
Place rounds on double thickness of paper towels; pat dry. Arrange tomatoes on crust in slightly overlapping rows, covering completely. Season generously with salt and pepper. Sprinkle Parmesan, 1 T olive oil and thyme over. Bake tart until tomatoes are heated through and cheeses melt, about 9 min. Cut tart into large squares.