How to Make It
Place 3 1/2 cups flour, 1 1/2 teaspoons salt, and baking powder in a food processor; pulse until combined. Stir together 10 tablespoons ice-cold water and 2/3 cup oil. With processor running, slowly pour water-and-oil mixture through food chute, processing until dough is crumbly. Turn dough out onto a lightly floured surface. Knead 1 minute. Press into a 5-inch disk; wrap in plastic wrap, and chill 30 minutes.
Preheat oven to 400°F. Heat 1 tablespoon oil in a large nonstick skillet over medium-high. Add chicken; cook, stirring often, until no longer pink, about 5 minutes. Place chicken and pan drippings in a bowl.
Without wiping pan, heat remaining 1 tablespoon oil over medium-high; add haricots verts, carrot, thyme, and garlic; cover, and cook, stirring occasionally, for 5 minutes or until tender. Add chicken and drippings back to pan; stir in peas. Sprinkle with remaining 2 tablespoons flour; stir to coat. Add chicken stock and bring to a boil; cook for 3 to 4 minutes or until thickened. Fold in parsley, pepper, and remaining 1 1/2 teaspoons salt.
Whisk together egg and 1 teaspoon water in a small bowl. Remove dough from refrigerator; let stand 5 minutes. Divide dough into 12 equal portions (about 2 ounces each), shaping each into a ball. Roll each ball into a 6-inch circle on a lightly floured surface. Spoon 1/3 cup chicken mixture onto center of each circle. Brush edges of dough circles with egg wash; fold dough over filling to form half-moons. Press edges together to seal. Brush remaining egg mixture over tops of pies and score tops to vent, or follow freezing instructions. Line a baking sheet with parchment paper; lightly coat paper with cooking spray. Place pies on prepared pan.
Bake at 400°F for 22 to 25 minutes or until crust is lightly browned. Top with additional parsley, if desired.
FREEZE: Freeze on a baking sheet for 12 hours or until solid. Transfer to a ziplock plastic freezer bag; freeze up to 6 months.
THAW: Not necessary! Bake straight from frozen.
BAKE: Place frozen pies on a parchment paper-lined baking sheet. Brush with egg wash; score. Bake at 450°F for 22 to 25 minutes or until crust is lightly browned. Top with additional parsley, if desired.