How to Make It
Prepare the Pie: Preheat oven to 400°F. Roll out pie dough on a lightly floured surface into a 12-inch circle. Fit into a lightly greased (with cooking spray) 9-inch pie plate, and fold dough under to create a double-thick edge and crimp. Place parchment paper over piecrust, and top with pie weights. Bake in preheated oven until crust is lightly golden and set, about 10 minutes. Remove weights and parchment; continue baking 5 more minutes. Transfer to a wire rack.
Reduce oven temperature to 350°F. Stir together apples, brown sugar, green chiles, granulated sugar, and lemon juice in a large bowl until well combined. Stir together flour, cinnamon, and nutmeg in a small bowl. Add flour mixture to apple mixture, and stir to combine. Let stand 10 minutes, stirring occasionally to dissolve sugars. Spoon mixture into pie crust, arranging apples as compactly as possible. Place pie on a baking sheet, and bake at 350°F for 35 minutes.
Prepare the Streusel Topping: While pie bakes, stir together flour, light brown sugar, walnuts, cinnamon, and kosher salt in a small bowl. Stir in melted butter until thoroughly combined. Freeze 20 minutes.
Remove pie from oven, and crumble Streusel Topping evenly over apple pie. Bake at 350°F until topping is golden brown and apples are tender, 40 to 50 minutes, covering with aluminum foil after 20 to 25 minutes to prevent overbrowning. Transfer to a wire rack and cool completely, about 2 hours, or serve warm.