1. Take out a package of Pepperidge Farm® Puff Pastry Sheets and remove one from the box. Let it thaw on the counter for 40 minutes - or overnight in the fridge. Return the second to the freezer.
2. Preheat the oven to 375°F.
3. Stir the cinnamon and sugar together.
4. Place the pear halves into a large bowl, and toss with the lemon juice. Add the cinnamon-sugar and toss.
5. Lightly flour your surface and unfold one pastry sheet.
6. Invert a 10-inch heavy, oven safe skillet over the pastry sheet and using it as a template, trim the excess pastry to make a rough circle. Prick the pastry circle thoroughly with a fork. Place the pastry circle onto a plate and refrigerate.
7. Heat the 10-inch skillet over medium-high heat and pour 2 tablespoons of water in the center of the skillet. Add 6 tablespoons of sugar to the water and cook for 7 minutes or until the sugar is a deep amber color. Do not stir.
8. Remove the skillet from the heat and add a dash of salt and the butter. Carefully tilt the skillet so that the sugar mixture and butter swirl together until well blended. Let the mixture cool for 2 minutes. Sprinkle the walnuts in the skillet.
9.Drain the pear halves and arrange 11 of the halves around the inside edge of the skillet, cut-side up, overlapping slightly, with the tops pointing toward the center. Place the remaining pear half, cut-side up, in the gap in the center of the skillet, trimming it to fit, if needed.
10. Cook the pears over medium heat for 10 minutes or until tender. Do not stir.
11. Remove the skillet from the heat and place the chilled pastry circle over the pear halves, pressing down slightly and tucking the edge in around the inside of the skillet.