This classic French apple tart is baked upside down, with the fruit at the bottom, and the puff pastry baked on top. Once inverted, the glossy, caramelized apples are revealed…gorgeous!
Preheat the oven to 375 °F (190 °C). On a lightly floured surface, roll the pastry out into a circle and cut it so that it is 9-inches (23 cm) across (using the ring of a 9-inch (23 cm) fluted pan creates a lovely edge to the pastry). Dock this with a fork and chill until ready to use.
Peel the apples, cut them in half and core them. Melt 2 Tbsp (30 g) of the butter and pour this over the apples, tossing with 2 Tbsp (25 g) of the sugar to coat. Set aside.
Place a 9-inch (23 cm) skillet (or other round pan that go from the stovetop to the oven) over medium-high heat and stir together the remaining ¼ cup (60 g) of butter, ½ cup (100 g) of the sugar and the lemon juice. Once bubbling at the edges, add the apples, arranging them so the curved sides are at the bottom and they are overlapping slightly, to pack them in. Increase the heat to high and cook for 2-3 minutes, until bubbling vigorously at the edges. Place the pan (without pastry) in the oven to bake for 15 minutes.
Pull the pan from the oven and place the chilled puff pastry on top of the apples, tucking it in a little around the edges. Return the pan to the oven and bake for 30-35 minutes, until the pastry is a golden brown. Let the tarte cool in the pan for 20-30 minutes. Use a palette knife to loosen any apples that might stick to the sides of the pan. Place a large plate over the pan and invert both (use a tea towel). Lift up the pan to reveal the tarte.
The Tarte Tatin can be served warm or at room temperature.