Preheat oven to 425 F. Line a 9-inch DEEP pie with pastry.
In a large bowl, combine apples, zucchini, carrots, nuts & flour; toss to coat.
In a medium bowl, beat brown sugar & margarine until well blended. Add cinnamon, nutmeg, salt, lemon juice, vanilla, orange zest & 2 eggs; blend well. Add to apple mixture; mix well.
Spoon filling into pie crust-lined pan. Top with second crust & flute; slit crust in several places. In a small bowl, blend egg & water; brush over top crust. Bake for 40-50 minutes or until deep golden brown. Cover pie loosely with foil during the last 15 minutes of baking to prevent excessive browning.
Serve with whipped cream if desired.
Recipe Notes
Oven temperatures often vary, so if you prefer, bake pie at a bit lower temperature.