- 6 to 8 large firm sweet apples, such as Northern Spy, Winesap, Granny Smith, Golden Delicious, or Mutsu, peeled and halved
- 1 to 2 lemons, halved
- 1 cup sugar
- 4 tablespoons unsalted butter
- 1 sheet frozen puff pastry (from a standard 17 1/4-ounce package), thawed
- All-purpose flour, for dusting
A Cast-iron Skillet Works Best When Making This Tart Because It Helps The Fruit To Caramelize, But Any Heavy-duty Nonstick Pan With An Ovenproof Handle Will Do.