Adapted from Gourmet, October 2001
Step 1: Bring water, sugar, lemon juice, and butter to a boil in a small saucepan, stirring until sugar is dissolved, then pour over apples. Turn apples until slightly wilted, then drain in a colander set over a bowl, reserving liquid.
Step 2: Preheat oven to 425°F.
Step 3: Roll out pastry sheet on a lightly floured surface into a 121/2-inch square and cut out 4 (6-inch) rounds.
Step 4: Transfer rounds to a lightly buttered baking sheet and top with overlapping apple slices.
Step 5: Bake in middle of oven until golden brown, about 25 minutes.
Step 6: Boil reserved liquid in saucepan until reduced to about 1/3 cup, then brush on baked tart.