For a Pear Tarte Tatin, substitute 6 large firm pears (Bosc or Anjou would be good) for the apples. Peel the pears, cut them in half lengthwise, and core them. Arrange them like spokes in the pan.
Peel,quarter and core the apples. Put them in a large mixing bowl and toss with the lemon juice.
Place the sugar in a 10-inch skillet or Tarte Tatin pan over low heat. When some of the sugar begins to melt, begin stirring with a wooden spoon until all of the sugar is melted and begins to turn a pale golden color. Remove the pan from the heat.
Arrange the apple piecess in the skillet, rounded side down, in concentric circles, fitting them together as close as possible. Fill the center with 2 or 3 apple pieces as needed. Arrange the remaining pieces, rounded side up, in concentric circles, filling in the gaps left in the first layer. Cut the butter into small pieces and scatter over the apples. Place the pan over medium heat. Cook until the sugar turns a deep caramel color and the juice released from the apples are nearly evaporated, about 15 to 20 minutes.
Preheat the oven to 375°F. Position the rack in the bottom third of the oven.
Roll out the dough and cover the apples according to directions for Tarte Tatin Pastry (see recipe below). Bake until the crust is golden brown, about 25 to 30 minutes. Remove from the oven
and let cool for 10 minutes.
Run a knife around the edge of the tarte to loosen it. Place in a large plate or platter over the skillet and carefully but quickly invert the tarte onto the plate. Let stand a few minutes to cool slightly. Cut into wedges and serve.