Place cookie sheet on oven rack. Heat oven to 400°F.
In 2-quart saucepan, mix soup and flour. Stir in vegetables. Cook over medium-high heat 5 to 6 minutes, stirring frequently, until bubbly and thickened; stir in chicken. Spoon into 1 frozen crust. While second crust is still in pan and frozen, remove crimp with sharp knife. Remove crust from pan and center frozen crust upside down on top of filled pie. Let thaw 10 minutes; crimp edges together. Cut 2 or 3 slits in top crust. Cover edge of crust with pie shield or foil strips.
Bake on cookie sheet 25 to 35 minutes or until crust is golden brown and filling is bubbly. Let stand 15 minutes before serving.