1. Combine flour and salt in a medium bowl. Cut in shortening and butter until mixture resembles sand. Working 1 tablespoon at a time, mix in the ice water until the dough is just moistened and forms a ball. Wrap in plastic and refrigerate for 30 minutes. Preheat oven to 425 degrees F and grease a 9" pie plate. Split the dough in 1/2 and form into 2 smaller balls. Roll out each ball on a lightly-floured surface until it is about 10" in diameter.
2. Place 1 disc into prepared pie plate, and press into plate. Using a pizza cutter (or fluted cutter), cut the second disc into strips that are approximately 3/4” wide. In a medium bowl, combine the blueberries, peaches, flour, sugar, lime zest, and nutmeg. Stir just to combine without breaking up the blueberries too much. Pour this mixture over the pie dough that is in the pie plate.
3. Using the pie dough strips you made earlier, form a lattice top on the pie (If you haven't done this before, you can find lots of videos on YouTube that will guide you through the process; it's not as hard as you might think). Press the strips into the edge of the bottom crust, then trim the excess dough with a paring knife.
4. Place the pie in the oven and bake about 30 minutes or until the edges are golden brown. Either cover the edges with a pie shield or make one yourself out of aluminum foil (directions below). Continue to bake the pie for an additional 20 minutes or until the pie is golden brown in the middle. While the pie is baking, make the caramel sauce.
5. In a small saucepan over high heat, combine the sugar and water. Cook until the mixture boils, swirling to help dissolve the sugar. Spray down the walls of the saucepan with cooking spray and continue to cook until the mixture starts to caramelize (don't agitate it during this process). Begin swirling the pan so that the sugar browns evenly. Once the mixture turns a deep caramel color, remove from heat and quickly stir in the milk, bourbon, and margarine.
6. Return the mixture to medium heat and cook until it is smooth. When you add the milk initially, the mixture will look terribly separated and generally awful. Don't worry, keep cooking it and stirring briskly and the whole thing will come together nicely. Remove from heat and allow it to cool slightly. Allow the pie to cool for about 20 minutes on a cooling rack before drizzling it with the caramel sauce. Slice the pie and feel free to douse with more caramel sauce on the plate.
To make pie shield, take a square of foil just large enough to cover the pie, then fold it in 1/2, then in quarters, then in eighths and sixteenths so that it forms a pie segment. Cut out a wedge about 4" from the central vertex. Unfold the foil so that you have a sheet of foil with an 8" diameter circle cut out.
Source of recipe: I love to make pie, and I wanted to see if I could make one to utilize frozen peaches.