Makes: 6-8 servings. Preparation time: 90 minutes.
Pre-heat the oven to 375° F. Roll out the Pastry Sheet to be larger than the skillet in the next steps. Trim the Pastry with a knife or pizza cutting wheel to just larger than the skillet diameter and discard the excess dough. Dice the Butter into small pieces. On a cutting board, core, peel, de-pit and slice each Apple into 8 parts. Coat with the Lemon Juice immediately to prevent discoloration. Place the Sugar in a large round cast-iron skillet and melt it over medium heat on the stove. Always use a pot-holder. Stir the Sugar until it is a light butterscotch color and the temperature reaches 320° F, measured with a candy thermometer. Don't allow it to burn. Turn off the heat and the temperature will still rise to about 350° F. Slowly whisk in the Butter pieces, one at a time. Make sure each piece is incorporated before adding the next. Add a pinch of Salt and stir. One at a time, add the Apple slices with a fork and make sure they are fully covered in the Caramel. Overlap them in a spiral, starting at the center and working outward. When the pan is full, turn on the heat again and cook covered for 15 minutes. Turn off the heat, uncover and let the temperature drop somewhat. Cover the skillet contents with the trimmed Pastry, tucking the edges around the Apples with a fork. The Pastry remains INSIDE the skillet, not on the skillet rim. Prick the center of the Pastry with a fork to allow venting. Bake the whole skillet in the oven for 40-45 minutes, until the edges are amber and the Pastry is crisp. Remove and let cool for 45-60 minutes. Place a large serving plate over the WARM skillet and invert the two together. Remove the skillet. Scrape the remaining contents back into the Tarte, if necessary.
Serve as a warm pie slice for each guest. A dollop of Crème Fraîche or Vanilla Ice Cream is optional.