Don't think pizza. This delicate tart may have the flavors of a fine pie from your local joint, but it's more refined. Not snobby; everyone can relate to warm mozzarella combining with plump juicy tomato slices. The puff pastry just adds an excitement, a newness to what is already familiar. With a bit of pesto drizzled over, this surely isn't pizza. It's better.
Core tomato and cut into ¼" rounds. Cut rounds into half-moons. Pat tomato dry, and sprinkle with ¼ tsp. salt and a pinch of pepper. Patting tomato dry prevents tarts from being soggy.
Hold romaine heart at root end and chop coarsely.
Make the Dressing
Add mayonnaise, garlic (to taste), half the Parmesan, white wine vinegar, 1 tsp. water, and a pinch of salt and pepper to a mixing bowl and thoroughly combine.
Make the Crust
Remove puff pastry from refrigerator. Remove any paper in between sheets.
Place two squares on prepared baking sheet and wet an ½" border on each with water.
Place each remaining puff pastry square on squares on sheet, overlapping on ½" wet border. Press firmly to seal squares together, forming two rectangles. Pressing firmly is key; otherwise, dough will separate as it cooks.
Assemble the Tarts
Divide mozzarella evenly between tarts. Shingle tomato down middle of tart. Top with remaining Parmesan.
Bake in hot oven until crust is golden brown, 24-28 minutes.
Toss Salad and Finish Dish
When tarts are finished baking, add romaine to mixing bowl with dressing and toss to coat.
Plate dish as pictured on front of card, garnishing tart with basil pesto and red pepper flakes (to taste). Bon appétit!