Filling: Heat oven to 400F. Heat broth in large saucepan over medium-high heat. Combine water, flour, salt and pepper in small bowl; stir until smooth. Add flour mixture to broth. Cook, stirring constantly, until thickened, 10 to 12 minutes. Heat oil in small skillet over medium heat. Add onion, celery and carrot. Cook, stirring frequently, until vegetables are tender, 4 to 5 minutes. Stir in peas and corn. Stir vegetables and chicken into sauce; mix well. Spoon mixture into 2-quart casserole dish; set aside. Crust: Combine flour, salt and baking powder in medium bowl. Cut in shortening with pastry blender or two knives until size of peas. Add ice water, 1 tablespoon at a time, until ball forms. Roll out on lightly floured surface to 1/8-inch thick. Place over chicken mixture. Cut hole in top of crust for steam to escape. Brush with egg and water mixture. Bake until crust is golden and filling is bubbly, about 35 minutes. Let stand 10 minutes before serving. Recipe by: Chicago Tribune test kitchen Posted to MC-Recipe Digest by "Bill Hatcher" on Mar 18, 1998