Flat Apple Pie with Perfect Pie Crust

INGREDIENTS

• 1 egg
• 1 recipe Perfect Pie Crust, recipe follows
• 5 Granny Smith apples, peeled and sliced
• 1/4 teaspoon salt
• 3 cups all-purpose flour, plus more for dusting
• 1/2 cup firmly packed brown sugar
• 5 tablespoons cold water
• 6 tablespoons butter
• 3/4 cup vegetable shortening
• 1 teaspoon salt
• 1 1/2 sticks cold butter
• 1 tablespoon distilled white vinegar
• Juice of 1/2 lemon
• 2 tablespoons all-purpose flour
• 1/2 cup granulated sugar